diff --git a/doc/api/next_api_changes/removals/28874-ES.rst b/doc/api/next_api_changes/removals/28874-ES.rst
new file mode 100644
index 000000000000..dbd8778dead1
--- /dev/null
+++ b/doc/api/next_api_changes/removals/28874-ES.rst
@@ -0,0 +1,180 @@
+Passing extra positional arguments to ``Figure.add_axes``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Positional arguments passed to `.Figure.add_axes` other than a rect or an existing
+``Axes`` were previously ignored, and is now an error.
+
+
+Artists explicitly passed in will no longer be filtered by legend() based on their label
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Previously, artists explicitly passed to ``legend(handles=[...])`` are filtered out if
+their label starts with an underscore. This filter is no longer applied; explicitly
+filter out such artists (``[art for art in artists if not
+art.get_label().startswith('_')]``) if necessary.
+
+Note that if no handles are specified at all, then the default still filters out labels
+starting with an underscore.
+
+
+The parameter of ``Annotation.contains`` and ``Legend.contains`` is renamed to *mouseevent*
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+... consistently with `.Artist.contains`.
+
+
+Support for passing the "frac" key in ``annotate(..., arrowprops={"frac": ...})``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+... has been removed.  This key has had no effect since Matplotlib 1.5.
+
+
+Passing non-int or sequence of non-int to ``Table.auto_set_column_width``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Column numbers are ints, and formerly passing any other type was effectively ignored.
+This has now become an error.
+
+
+Widgets
+~~~~~~~
+
+The *visible* attribute getter of ``*Selector`` widgets has been removed; use
+``get_visible`` instead.
+
+
+Auto-closing of figures when switching backend
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Allowable backend switches (i.e. those that do not swap a GUI event loop with another
+one) will not close existing figures. If necessary, call ``plt.close("all")`` before
+switching.
+
+
+``FigureCanvasBase.switch_backends``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+... has been removed with no replacement.
+
+
+Accessing ``event.guiEvent`` after event handlers return
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+... is no longer supported, and ``event.guiEvent`` will be set to None once the event
+handlers return. For some GUI toolkits, it is unsafe to use the event, though you may
+separately stash the object at your own risk.
+
+
+``PdfPages(keep_empty=True)``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+A zero-page PDF is not valid, thus passing ``keep_empty=True`` to `.backend_pdf.PdfPages`
+and `.backend_pgf.PdfPages`, and the ``keep_empty`` attribute of these classes, is no
+longer allowed, and empty PDF files will not be created.
+
+Furthermore, `.backend_pdf.PdfPages` no longer immediately creates the target file upon
+instantiation, but only when the first figure is saved.  To fully control file creation,
+directly pass an opened file object as argument (``with open(path, "wb") as file,
+PdfPages(file) as pdf: ...``).
+
+
+``backend_ps.psDefs``
+~~~~~~~~~~~~~~~~~~~~~
+
+The ``psDefs`` module-level variable in ``backend_ps`` has been removed with no
+replacement.
+
+
+Automatic papersize selection in PostScript
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Setting :rc:`ps.papersize` to ``'auto'`` or passing ``papersize='auto'`` to
+`.Figure.savefig` is no longer supported. Either pass an explicit paper type name, or
+omit this parameter to use the default from the rcParam.
+
+
+``RendererAgg.tostring_rgb`` and ``FigureCanvasAgg.tostring_rgb``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+... have been remove with no direct replacement. Consider using ``buffer_rgba`` instead,
+which should cover most use cases.
+
+
+``NavigationToolbar2QT.message`` has been removed
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+... with no replacement.
+
+
+``TexManager.texcache``
+~~~~~~~~~~~~~~~~~~~~~~~
+
+... is considered private and has been removed. The location of the cache directory is
+clarified in the doc-string.
+
+
+``cbook`` API changes
+~~~~~~~~~~~~~~~~~~~~~
+
+``cbook.Stack`` has been removed with no replacement.
+
+``Grouper.clean()`` has been removed with no replacement. The Grouper class now cleans
+itself up automatically.
+
+The *np_load* parameter of ``cbook.get_sample_data`` has been removed; `.get_sample_data`
+now auto-loads numpy arrays. Use ``get_sample_data(..., asfileobj=False)`` instead to get
+the filename of the data file, which can then be passed to `open`, if desired.
+
+
+Calling ``paths.get_path_collection_extents`` with empty *offsets*
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Calling  `~.get_path_collection_extents` with an empty *offsets* parameter has an
+ambiguous interpretation and is no longer allowed.
+
+
+``bbox.anchored()`` with no explicit container
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Not passing a *container* argument to `.BboxBase.anchored` is no longer supported.
+
+
+``INVALID_NON_AFFINE``, ``INVALID_AFFINE``, ``INVALID`` attributes of ``TransformNode``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+These attributes have been removed.
+
+
+``axes_grid1`` API changes
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+``anchored_artists.AnchoredEllipse`` has been removed. Instead, directly construct an
+`.AnchoredOffsetbox`, an `.AuxTransformBox`, and an `~.patches.Ellipse`, as demonstrated
+in :doc:`/gallery/misc/anchored_artists`.
+
+The ``axes_divider.AxesLocator`` class has been removed.  The ``new_locator`` method of
+divider instances now instead returns an opaque callable (which can still be passed to
+``ax.set_axes_locator``).
+
+``axes_divider.Divider.locate`` has been removed; use ``Divider.new_locator(...)(ax,
+renderer)`` instead.
+
+``axes_grid.CbarAxesBase.toggle_label`` has been removed. Instead, use standard methods
+for manipulating colorbar labels (`.Colorbar.set_label`) and tick labels
+(`.Axes.tick_params`).
+
+``inset_location.InsetPosition`` has been removed; use `~.Axes.inset_axes` instead.
+
+
+``axisartist`` API changes
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ``axisartist.axes_grid`` and ``axisartist.axes_rgb`` modules, which provide wrappers
+combining the functionality of `.axes_grid1` and `.axisartist`, have been removed;
+directly use e.g. ``AxesGrid(..., axes_class=axislines.Axes)`` instead.
+
+Calling an axisartist Axes to mean `~matplotlib.pyplot.axis` has been removed; explicitly
+call the method instead.
+
+``floating_axes.GridHelperCurveLinear.get_data_boundary`` has been removed.  Use
+``grid_finder.extreme_finder(*[None] * 5)`` to get the extremes of the grid.
diff --git a/doc/api/prev_api_changes/api_changes_3.6.0/behaviour.rst b/doc/api/prev_api_changes/api_changes_3.6.0/behaviour.rst
index 91802692ebb4..6ace010515fb 100644
--- a/doc/api/prev_api_changes/api_changes_3.6.0/behaviour.rst
+++ b/doc/api/prev_api_changes/api_changes_3.6.0/behaviour.rst
@@ -241,7 +241,7 @@ Specified exception types in ``Grid``
 
 In a few cases an `Exception` was thrown when an incorrect argument value was
 set in the `mpl_toolkits.axes_grid1.axes_grid.Grid` (=
-`mpl_toolkits.axisartist.axes_grid.Grid`) constructor. These are replaced as
+``mpl_toolkits.axisartist.axes_grid.Grid``) constructor. These are replaced as
 follows:
 
 * Providing an incorrect value for *ngrids* now raises a `ValueError`
diff --git a/doc/api/prev_api_changes/api_changes_3.7.0/deprecations.rst b/doc/api/prev_api_changes/api_changes_3.7.0/deprecations.rst
index dd6d9d8e0894..55a0a7133c65 100644
--- a/doc/api/prev_api_changes/api_changes_3.7.0/deprecations.rst
+++ b/doc/api/prev_api_changes/api_changes_3.7.0/deprecations.rst
@@ -90,7 +90,7 @@ Passing undefined *label_mode* to ``Grid``
 ... is deprecated. This includes `mpl_toolkits.axes_grid1.axes_grid.Grid`,
 `mpl_toolkits.axes_grid1.axes_grid.AxesGrid`, and
 `mpl_toolkits.axes_grid1.axes_grid.ImageGrid` as well as the corresponding
-classes imported from `mpl_toolkits.axisartist.axes_grid`.
+classes imported from ``mpl_toolkits.axisartist.axes_grid``.
 
 Pass ``label_mode='keep'`` instead to get the previous behavior of not modifying labels.
 
diff --git a/doc/api/prev_api_changes/api_changes_3.9.0/removals.rst b/doc/api/prev_api_changes/api_changes_3.9.0/removals.rst
index b9aa03cfbf92..791c04149981 100644
--- a/doc/api/prev_api_changes/api_changes_3.9.0/removals.rst
+++ b/doc/api/prev_api_changes/api_changes_3.9.0/removals.rst
@@ -111,7 +111,7 @@ Passing undefined *label_mode* to ``Grid``
 ... is no longer allowed. This includes `mpl_toolkits.axes_grid1.axes_grid.Grid`,
 `mpl_toolkits.axes_grid1.axes_grid.AxesGrid`, and
 `mpl_toolkits.axes_grid1.axes_grid.ImageGrid` as well as the corresponding classes
-imported from `mpl_toolkits.axisartist.axes_grid`.
+imported from ``mpl_toolkits.axisartist.axes_grid``.
 
 Pass ``label_mode='keep'`` instead to get the previous behavior of not modifying labels.
 
diff --git a/doc/api/toolkits/axisartist.rst b/doc/api/toolkits/axisartist.rst
index 8cac4d68a266..5f58d134d370 100644
--- a/doc/api/toolkits/axisartist.rst
+++ b/doc/api/toolkits/axisartist.rst
@@ -34,8 +34,6 @@ You can find a tutorial describing usage of axisartist at the
 
    axisartist.angle_helper
    axisartist.axes_divider
-   axisartist.axes_grid
-   axisartist.axes_rgb
    axisartist.axis_artist
    axisartist.axisline_style
    axisartist.axislines
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
index 817eb51705fe..95ed49612b35 100644
--- a/lib/matplotlib/backend_bases.py
+++ b/lib/matplotlib/backend_bases.py
@@ -1178,26 +1178,12 @@ class Event:
     def __init__(self, name, canvas, guiEvent=None):
         self.name = name
         self.canvas = canvas
-        self._guiEvent = guiEvent
-        self._guiEvent_deleted = False
+        self.guiEvent = guiEvent
 
     def _process(self):
         """Process this event on ``self.canvas``, then unset ``guiEvent``."""
         self.canvas.callbacks.process(self.name, self)
-        self._guiEvent_deleted = True
-
-    @property
-    def guiEvent(self):
-        # After deprecation elapses: remove _guiEvent_deleted; make guiEvent a plain
-        # attribute set to None by _process.
-        if self._guiEvent_deleted:
-            _api.warn_deprecated(
-                "3.8", message="Accessing guiEvent outside of the original GUI event "
-                "handler is unsafe and deprecated since %(since)s; in the future, the "
-                "attribute will be set to None after quitting the event handler.  You "
-                "may separately record the value of the guiEvent attribute at your own "
-                "risk.")
-        return self._guiEvent
+        self.guiEvent = None
 
 
 class DrawEvent(Event):
@@ -2097,12 +2083,6 @@ def print_figure(
         if dpi == 'figure':
             dpi = getattr(self.figure, '_original_dpi', self.figure.dpi)
 
-        if kwargs.get("papertype") == 'auto':
-            # When deprecation elapses, remove backend_ps._get_papertype & its callers.
-            _api.warn_deprecated(
-                "3.8", name="papertype='auto'", addendum="Pass an explicit paper type, "
-                "'figure', or omit the *papertype* argument entirely.")
-
         # Remove the figure manager, if any, to avoid resizing the GUI widget.
         with (cbook._setattr_cm(self, manager=None),
               self._switch_canvas_and_return_print_method(format, backend)
@@ -2207,20 +2187,6 @@ def get_default_filename(self):
         default_filetype = self.get_default_filetype()
         return f'{default_basename}.{default_filetype}'
 
-    @_api.deprecated("3.8")
-    def switch_backends(self, FigureCanvasClass):
-        """
-        Instantiate an instance of FigureCanvasClass
-
-        This is used for backend switching, e.g., to instantiate a
-        FigureCanvasPS from a FigureCanvasGTK.  Note, deep copying is
-        not done, so any changes to one of the instances (e.g., setting
-        figure size or line props), will be reflected in the other
-        """
-        newCanvas = FigureCanvasClass(self.figure)
-        newCanvas._is_saving = self._is_saving
-        return newCanvas
-
     def mpl_connect(self, s, func):
         """
         Bind function *func* to event *s*.
diff --git a/lib/matplotlib/backend_bases.pyi b/lib/matplotlib/backend_bases.pyi
index c2fc61e386d8..70be504666fc 100644
--- a/lib/matplotlib/backend_bases.pyi
+++ b/lib/matplotlib/backend_bases.pyi
@@ -199,13 +199,11 @@ class TimerBase:
 class Event:
     name: str
     canvas: FigureCanvasBase
+    guiEvent: Any
     def __init__(
         self, name: str, canvas: FigureCanvasBase, guiEvent: Any | None = ...
     ) -> None: ...
 
-    @property
-    def guiEvent(self) -> Any: ...
-
 class DrawEvent(Event):
     renderer: RendererBase
     def __init__(
@@ -348,7 +346,6 @@ class FigureCanvasBase:
     def get_default_filetype(cls) -> str: ...
     def get_default_filename(self) -> str: ...
     _T = TypeVar("_T", bound=FigureCanvasBase)
-    def switch_backends(self, FigureCanvasClass: type[_T]) -> _T: ...
     def mpl_connect(self, s: str, func: Callable[[Event], Any]) -> int: ...
     def mpl_disconnect(self, cid: int) -> None: ...
     def new_timer(
diff --git a/lib/matplotlib/backend_tools.pyi b/lib/matplotlib/backend_tools.pyi
index 446f713292e1..f86a207c7545 100644
--- a/lib/matplotlib/backend_tools.pyi
+++ b/lib/matplotlib/backend_tools.pyi
@@ -75,8 +75,8 @@ class ToolXScale(AxisScaleBase):
     def set_scale(self, ax, scale: str | ScaleBase) -> None: ...
 
 class ToolViewsPositions(ToolBase):
-    views: dict[Figure | Axes, cbook.Stack]
-    positions: dict[Figure | Axes, cbook.Stack]
+    views: dict[Figure | Axes, cbook._Stack]
+    positions: dict[Figure | Axes, cbook._Stack]
     home_views: dict[Figure, dict[Axes, tuple[float, float, float, float]]]
     def add_figure(self, figure: Figure) -> None: ...
     def clear(self, figure: Figure) -> None: ...
diff --git a/lib/matplotlib/backends/backend_agg.py b/lib/matplotlib/backends/backend_agg.py
index 92253c02c1b5..ae361f0cceb4 100644
--- a/lib/matplotlib/backends/backend_agg.py
+++ b/lib/matplotlib/backends/backend_agg.py
@@ -266,10 +266,6 @@ def buffer_rgba(self):
     def tostring_argb(self):
         return np.asarray(self._renderer).take([3, 0, 1, 2], axis=2).tobytes()
 
-    @_api.deprecated("3.8", alternative="buffer_rgba")
-    def tostring_rgb(self):
-        return np.asarray(self._renderer).take([0, 1, 2], axis=2).tobytes()
-
     def clear(self):
         self._renderer.clear()
 
@@ -398,16 +394,6 @@ def get_renderer(self):
             self._lastKey = key
         return self.renderer
 
-    @_api.deprecated("3.8", alternative="buffer_rgba")
-    def tostring_rgb(self):
-        """
-        Get the image as RGB `bytes`.
-
-        `draw` must be called at least once before this function will work and
-        to update the renderer for any subsequent changes to the Figure.
-        """
-        return self.renderer.tostring_rgb()
-
     def tostring_argb(self):
         """
         Get the image as ARGB `bytes`.
diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
index 7e3e09f034f5..9c542e2a8f8e 100644
--- a/lib/matplotlib/backends/backend_pdf.py
+++ b/lib/matplotlib/backends/backend_pdf.py
@@ -2663,9 +2663,9 @@ class PdfPages:
     confusion when using `~.pyplot.savefig` and forgetting the format argument.
     """
 
-    _UNSET = object()
-
-    def __init__(self, filename, keep_empty=_UNSET, metadata=None):
+    @_api.delete_parameter("3.10", "keep_empty",
+                           addendum="This parameter does nothing.")
+    def __init__(self, filename, keep_empty=None, metadata=None):
         """
         Create a new PdfPages object.
 
@@ -2676,10 +2676,6 @@ def __init__(self, filename, keep_empty=_UNSET, metadata=None):
             The file is opened when a figure is saved for the first time (overwriting
             any older file with the same name).
 
-        keep_empty : bool, optional
-            If set to False, then empty pdf files will be deleted automatically
-            when closed.
-
         metadata : dict, optional
             Information dictionary object (see PDF reference section 10.2.1
             'Document Information Dictionary'), e.g.:
@@ -2693,13 +2689,6 @@ def __init__(self, filename, keep_empty=_UNSET, metadata=None):
         self._filename = filename
         self._metadata = metadata
         self._file = None
-        if keep_empty and keep_empty is not self._UNSET:
-            _api.warn_deprecated("3.8", message=(
-                "Keeping empty pdf files is deprecated since %(since)s and support "
-                "will be removed %(removal)s."))
-        self._keep_empty = keep_empty
-
-    keep_empty = _api.deprecate_privatize_attribute("3.8")
 
     def __enter__(self):
         return self
@@ -2721,11 +2710,6 @@ def close(self):
             self._file.finalize()
             self._file.close()
             self._file = None
-        elif self._keep_empty:  # True *or* UNSET.
-            _api.warn_deprecated("3.8", message=(
-                "Keeping empty pdf files is deprecated since %(since)s and support "
-                "will be removed %(removal)s."))
-            PdfFile(self._filename, metadata=self._metadata).close()  # touch the file.
 
     def infodict(self):
         """
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
index daefdb0640ca..48b6e8ac152c 100644
--- a/lib/matplotlib/backends/backend_pgf.py
+++ b/lib/matplotlib/backends/backend_pgf.py
@@ -14,7 +14,7 @@
 from PIL import Image
 
 import matplotlib as mpl
-from matplotlib import _api, cbook, font_manager as fm
+from matplotlib import cbook, font_manager as fm
 from matplotlib.backend_bases import (
     _Backend, FigureCanvasBase, FigureManagerBase, RendererBase
 )
@@ -898,9 +898,7 @@ class PdfPages:
     ...     pdf.savefig()
     """
 
-    _UNSET = object()
-
-    def __init__(self, filename, *, keep_empty=_UNSET, metadata=None):
+    def __init__(self, filename, *, metadata=None):
         """
         Create a new PdfPages object.
 
@@ -910,10 +908,6 @@ def __init__(self, filename, *, keep_empty=_UNSET, metadata=None):
             Plots using `PdfPages.savefig` will be written to a file at this
             location. Any older file with the same name is overwritten.
 
-        keep_empty : bool, default: True
-            If set to False, then empty pdf files will be deleted automatically
-            when closed.
-
         metadata : dict, optional
             Information dictionary object (see PDF reference section 10.2.1
             'Document Information Dictionary'), e.g.:
@@ -929,17 +923,10 @@ def __init__(self, filename, *, keep_empty=_UNSET, metadata=None):
         """
         self._output_name = filename
         self._n_figures = 0
-        if keep_empty and keep_empty is not self._UNSET:
-            _api.warn_deprecated("3.8", message=(
-                "Keeping empty pdf files is deprecated since %(since)s and support "
-                "will be removed %(removal)s."))
-        self._keep_empty = keep_empty
         self._metadata = (metadata or {}).copy()
         self._info_dict = _create_pdf_info_dict('pgf', self._metadata)
         self._file = BytesIO()
 
-    keep_empty = _api.deprecate_privatize_attribute("3.8")
-
     def _write_header(self, width_inches, height_inches):
         pdfinfo = ','.join(
             _metadata_to_str(k, v) for k, v in self._info_dict.items())
@@ -969,11 +956,6 @@ def close(self):
         self._file.write(rb'\end{document}\n')
         if self._n_figures > 0:
             self._run_latex()
-        elif self._keep_empty:
-            _api.warn_deprecated("3.8", message=(
-                "Keeping empty pdf files is deprecated since %(since)s and support "
-                "will be removed %(removal)s."))
-            open(self._output_name, 'wb').close()
         self._file.close()
 
     def _run_latex(self):
diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
index 5f224f38af1e..4f4c27cce955 100644
--- a/lib/matplotlib/backends/backend_ps.py
+++ b/lib/matplotlib/backends/backend_ps.py
@@ -39,12 +39,6 @@
 debugPS = False
 
 
-@_api.caching_module_getattr
-class __getattr__:
-    # module-level deprecations
-    psDefs = _api.deprecated("3.8", obj_type="")(property(lambda self: _psDefs))
-
-
 papersize = {'letter': (8.5, 11),
              'legal': (8.5, 14),
              'ledger': (11, 17),
@@ -72,15 +66,6 @@ class __getattr__:
              'b10': (1.26, 1.76)}
 
 
-def _get_papertype(w, h):
-    for key, (pw, ph) in sorted(papersize.items(), reverse=True):
-        if key.startswith('l'):
-            continue
-        if w < pw and h < ph:
-            return key
-    return 'a0'
-
-
 def _nums_to_str(*args, sep=" "):
     return sep.join(f"{arg:1.3f}".rstrip("0").rstrip(".") for arg in args)
 
@@ -828,7 +813,7 @@ def _print_ps(
         if papertype is None:
             papertype = mpl.rcParams['ps.papersize']
         papertype = papertype.lower()
-        _api.check_in_list(['figure', 'auto', *papersize], papertype=papertype)
+        _api.check_in_list(['figure', *papersize], papertype=papertype)
 
         orientation = _api.check_getitem(
             _Orientation, orientation=orientation.lower())
@@ -858,9 +843,6 @@ def _print_figure(
 
         # find the appropriate papertype
         width, height = self.figure.get_size_inches()
-        if papertype == 'auto':
-            papertype = _get_papertype(*orientation.swap_if_landscape((width, height)))
-
         if is_eps or papertype == 'figure':
             paper_width, paper_height = width, height
         else:
@@ -1041,8 +1023,6 @@ def _print_figure_tex(
                 paper_width, paper_height = orientation.swap_if_landscape(
                     self.figure.get_size_inches())
             else:
-                if papertype == 'auto':
-                    papertype = _get_papertype(width, height)
                 paper_width, paper_height = papersize[papertype]
 
             psfrag_rotated = _convert_psfrags(
diff --git a/lib/matplotlib/backends/backend_qt.py b/lib/matplotlib/backends/backend_qt.py
index e693811df4f0..bc37a15c7a67 100644
--- a/lib/matplotlib/backends/backend_qt.py
+++ b/lib/matplotlib/backends/backend_qt.py
@@ -658,9 +658,6 @@ def set_window_title(self, title):
 
 
 class NavigationToolbar2QT(NavigationToolbar2, QtWidgets.QToolBar):
-    _message = QtCore.Signal(str)  # Remove once deprecation below elapses.
-    message = _api.deprecate_privatize_attribute("3.8")
-
     toolitems = [*NavigationToolbar2.toolitems]
     toolitems.insert(
         # Add 'customize' action after 'subplots'
@@ -783,7 +780,6 @@ def zoom(self, *args):
         self._update_buttons_checked()
 
     def set_message(self, s):
-        self._message.emit(s)
         if self.coordinates:
             self.locLabel.setText(s)
 
diff --git a/lib/matplotlib/cbook.py b/lib/matplotlib/cbook.py
index 7cf32c4d5f6a..fe556487410f 100644
--- a/lib/matplotlib/cbook.py
+++ b/lib/matplotlib/cbook.py
@@ -543,9 +543,7 @@ def is_scalar_or_string(val):
     return isinstance(val, str) or not np.iterable(val)
 
 
-@_api.delete_parameter(
-    "3.8", "np_load", alternative="open(get_sample_data(..., asfileobj=False))")
-def get_sample_data(fname, asfileobj=True, *, np_load=True):
+def get_sample_data(fname, asfileobj=True):
     """
     Return a sample data file.  *fname* is a path relative to the
     :file:`mpl-data/sample_data` directory.  If *asfileobj* is `True`
@@ -564,10 +562,7 @@ def get_sample_data(fname, asfileobj=True, *, np_load=True):
         if suffix == '.gz':
             return gzip.open(path)
         elif suffix in ['.npy', '.npz']:
-            if np_load:
-                return np.load(path)
-            else:
-                return path.open('rb')
+            return np.load(path)
         elif suffix in ['.csv', '.xrc', '.txt']:
             return path.open('r')
         else:
@@ -607,113 +602,6 @@ def flatten(seq, scalarp=is_scalar_or_string):
             yield from flatten(item, scalarp)
 
 
-@_api.deprecated("3.8")
-class Stack:
-    """
-    Stack of elements with a movable cursor.
-
-    Mimics home/back/forward in a web browser.
-    """
-
-    def __init__(self, default=None):
-        self.clear()
-        self._default = default
-
-    def __call__(self):
-        """Return the current element, or None."""
-        if not self._elements:
-            return self._default
-        else:
-            return self._elements[self._pos]
-
-    def __len__(self):
-        return len(self._elements)
-
-    def __getitem__(self, ind):
-        return self._elements[ind]
-
-    def forward(self):
-        """Move the position forward and return the current element."""
-        self._pos = min(self._pos + 1, len(self._elements) - 1)
-        return self()
-
-    def back(self):
-        """Move the position back and return the current element."""
-        if self._pos > 0:
-            self._pos -= 1
-        return self()
-
-    def push(self, o):
-        """
-        Push *o* to the stack at current position.  Discard all later elements.
-
-        *o* is returned.
-        """
-        self._elements = self._elements[:self._pos + 1] + [o]
-        self._pos = len(self._elements) - 1
-        return self()
-
-    def home(self):
-        """
-        Push the first element onto the top of the stack.
-
-        The first element is returned.
-        """
-        if not self._elements:
-            return
-        self.push(self._elements[0])
-        return self()
-
-    def empty(self):
-        """Return whether the stack is empty."""
-        return len(self._elements) == 0
-
-    def clear(self):
-        """Empty the stack."""
-        self._pos = -1
-        self._elements = []
-
-    def bubble(self, o):
-        """
-        Raise all references of *o* to the top of the stack, and return it.
-
-        Raises
-        ------
-        ValueError
-            If *o* is not in the stack.
-        """
-        if o not in self._elements:
-            raise ValueError('Given element not contained in the stack')
-        old_elements = self._elements.copy()
-        self.clear()
-        top_elements = []
-        for elem in old_elements:
-            if elem == o:
-                top_elements.append(elem)
-            else:
-                self.push(elem)
-        for _ in top_elements:
-            self.push(o)
-        return o
-
-    def remove(self, o):
-        """
-        Remove *o* from the stack.
-
-        Raises
-        ------
-        ValueError
-            If *o* is not in the stack.
-        """
-        if o not in self._elements:
-            raise ValueError('Given element not contained in the stack')
-        old_elements = self._elements.copy()
-        self.clear()
-        for elem in old_elements:
-            if elem != o:
-                self.push(elem)
-
-
 class _Stack:
     """
     Stack of elements with a movable cursor.
@@ -913,10 +801,6 @@ def __setstate__(self, state):
     def __contains__(self, item):
         return item in self._mapping
 
-    @_api.deprecated("3.8", alternative="none, you no longer need to clean a Grouper")
-    def clean(self):
-        """Clean dead weak references from the dictionary."""
-
     def join(self, a, *args):
         """
         Join given arguments into the same set.  Accepts one or more arguments.
diff --git a/lib/matplotlib/cbook.pyi b/lib/matplotlib/cbook.pyi
index d727b8065b7a..cc6b4e8f4e19 100644
--- a/lib/matplotlib/cbook.pyi
+++ b/lib/matplotlib/cbook.pyi
@@ -74,26 +74,18 @@ def open_file_cm(
 def is_scalar_or_string(val: Any) -> bool: ...
 @overload
 def get_sample_data(
-    fname: str | os.PathLike, asfileobj: Literal[True] = ..., *, np_load: Literal[True]
-) -> np.ndarray: ...
+    fname: str | os.PathLike, asfileobj: Literal[True] = ...
+) -> np.ndarray | IO: ...
 @overload
-def get_sample_data(
-    fname: str | os.PathLike,
-    asfileobj: Literal[True] = ...,
-    *,
-    np_load: Literal[False] = ...,
-) -> IO: ...
-@overload
-def get_sample_data(
-    fname: str | os.PathLike, asfileobj: Literal[False], *, np_load: bool = ...
-) -> str: ...
+def get_sample_data(fname: str | os.PathLike, asfileobj: Literal[False]) -> str: ...
 def _get_data_path(*args: Path | str) -> Path: ...
 def flatten(
     seq: Iterable[Any], scalarp: Callable[[Any], bool] = ...
 ) -> Generator[Any, None, None]: ...
 
-class Stack(Generic[_T]):
-    def __init__(self, default: _T | None = ...) -> None: ...
+class _Stack(Generic[_T]):
+    def __init__(self) -> None: ...
+    def clear(self) -> None: ...
     def __call__(self) -> _T: ...
     def __len__(self) -> int: ...
     def __getitem__(self, ind: int) -> _T: ...
@@ -101,10 +93,6 @@ class Stack(Generic[_T]):
     def back(self) -> _T: ...
     def push(self, o: _T) -> _T: ...
     def home(self) -> _T: ...
-    def empty(self) -> bool: ...
-    def clear(self) -> None: ...
-    def bubble(self, o: _T) -> _T: ...
-    def remove(self, o: _T) -> None: ...
 
 def safe_masked_invalid(x: ArrayLike, copy: bool = ...) -> np.ndarray: ...
 def print_cycles(
@@ -114,7 +102,6 @@ def print_cycles(
 class Grouper(Generic[_T]):
     def __init__(self, init: Iterable[_T] = ...) -> None: ...
     def __contains__(self, item: _T) -> bool: ...
-    def clean(self) -> None: ...
     def join(self, a: _T, *args: _T) -> None: ...
     def joined(self, a: _T, b: _T) -> bool: ...
     def remove(self, a: _T) -> None: ...
diff --git a/lib/matplotlib/figure.py b/lib/matplotlib/figure.py
index 73f1629180aa..4271bb78e8de 100644
--- a/lib/matplotlib/figure.py
+++ b/lib/matplotlib/figure.py
@@ -613,22 +613,22 @@ def add_axes(self, *args, **kwargs):
         """
 
         if not len(args) and 'rect' not in kwargs:
-            raise TypeError(
-                "add_axes() missing 1 required positional argument: 'rect'")
+            raise TypeError("add_axes() missing 1 required positional argument: 'rect'")
         elif 'rect' in kwargs:
             if len(args):
-                raise TypeError(
-                    "add_axes() got multiple values for argument 'rect'")
+                raise TypeError("add_axes() got multiple values for argument 'rect'")
             args = (kwargs.pop('rect'), )
+        if len(args) != 1:
+            raise _api.nargs_error("add_axes", 1, len(args))
 
         if isinstance(args[0], Axes):
-            a, *extra_args = args
+            a, = args
             key = a._projection_init
             if a.get_figure(root=False) is not self:
                 raise ValueError(
                     "The Axes must have been created in the present figure")
         else:
-            rect, *extra_args = args
+            rect, = args
             if not np.isfinite(rect).all():
                 raise ValueError(f'all entries in rect must be finite not {rect}')
             projection_class, pkw = self._process_projection_requirements(**kwargs)
@@ -637,11 +637,6 @@ def add_axes(self, *args, **kwargs):
             a = projection_class(self, rect, **pkw)
             key = (projection_class, pkw)
 
-        if extra_args:
-            _api.warn_deprecated(
-                "3.8",
-                name="Passing more than one positional argument to Figure.add_axes",
-                addendum="Any additional positional arguments are currently ignored.")
         return self._add_axes_internal(a, key)
 
     @_docstring.interpd
diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
index 270757fc298e..a3bf4c14e7fc 100644
--- a/lib/matplotlib/legend.py
+++ b/lib/matplotlib/legend.py
@@ -454,24 +454,10 @@ def __init__(
         self.borderaxespad = mpl._val_or_rc(borderaxespad, 'legend.borderaxespad')
         self.columnspacing = mpl._val_or_rc(columnspacing, 'legend.columnspacing')
         self.shadow = mpl._val_or_rc(shadow, 'legend.shadow')
-        # trim handles and labels if illegal label...
-        _lab, _hand = [], []
-        for label, handle in zip(labels, handles):
-            if isinstance(label, str) and label.startswith('_'):
-                _api.warn_deprecated("3.8", message=(
-                    "An artist whose label starts with an underscore was passed to "
-                    "legend(); such artists will no longer be ignored in the future.  "
-                    "To suppress this warning, explicitly filter out such artists, "
-                    "e.g. with `[art for art in artists if not "
-                    "art.get_label().startswith('_')]`."))
-            else:
-                _lab.append(label)
-                _hand.append(handle)
-        labels, handles = _lab, _hand
 
         if reverse:
-            labels.reverse()
-            handles.reverse()
+            labels = [*reversed(labels)]
+            handles = [*reversed(handles)]
 
         if len(handles) < 2:
             ncols = 1
diff --git a/lib/matplotlib/path.py b/lib/matplotlib/path.py
index 0e870161a48d..5f5a0f3de423 100644
--- a/lib/matplotlib/path.py
+++ b/lib/matplotlib/path.py
@@ -1086,10 +1086,7 @@ def get_path_collection_extents(
     if len(paths) == 0:
         raise ValueError("No paths provided")
     if len(offsets) == 0:
-        _api.warn_deprecated(
-            "3.8", message="Calling get_path_collection_extents() with an"
-            " empty offsets list is deprecated since %(since)s. Support will"
-            " be removed %(removal)s.")
+        raise ValueError("No offsets provided")
     extents, minpos = _path.get_path_collection_extents(
         master_transform, paths, np.atleast_3d(transforms),
         offsets, offset_transform)
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
index 744eee0e4b9f..69c80e6d3579 100644
--- a/lib/matplotlib/pyplot.py
+++ b/lib/matplotlib/pyplot.py
@@ -514,14 +514,6 @@ def draw_if_interactive() -> None:
     # See https://github.com/matplotlib/matplotlib/issues/6092
     matplotlib.backends.backend = newbackend  # type: ignore[attr-defined]
 
-    if not cbook._str_equal(old_backend, newbackend):
-        if get_fignums():
-            _api.warn_deprecated("3.8", message=(
-                "Auto-close()ing of figures upon backend switching is deprecated since "
-                "%(since)s and will be removed %(removal)s.  To suppress this warning, "
-                "explicitly call plt.close('all') first."))
-        close("all")
-
     # Make sure the repl display hook is installed in case we become interactive.
     install_repl_displayhook()
 
diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
index e84b0539385b..308e02fca72b 100644
--- a/lib/matplotlib/rcsetup.py
+++ b/lib/matplotlib/rcsetup.py
@@ -463,19 +463,6 @@ def validate_ps_distiller(s):
         return ValidateInStrings('ps.usedistiller', ['ghostscript', 'xpdf'])(s)
 
 
-def _validate_papersize(s):
-    # Re-inline this validator when the 'auto' deprecation expires.
-    s = ValidateInStrings("ps.papersize",
-                          ["figure", "auto", "letter", "legal", "ledger",
-                           *[f"{ab}{i}" for ab in "ab" for i in range(11)]],
-                          ignorecase=True)(s)
-    if s == "auto":
-        _api.warn_deprecated("3.8", name="ps.papersize='auto'",
-                             addendum="Pass an explicit paper type, figure, or omit "
-                             "the *ps.papersize* rcParam entirely.")
-    return s
-
-
 # A validator dedicated to the named line styles, based on the items in
 # ls_mapper, and a list of possible strings read from Line2D.set_linestyle
 _validate_named_linestyle = ValidateInStrings(
@@ -1291,7 +1278,9 @@ def _convert_validator_spec(key, conv):
     "tk.window_focus": validate_bool,  # Maintain shell focus for TkAgg
 
     # Set the papersize/type
-    "ps.papersize":       _validate_papersize,
+    "ps.papersize":       _ignorecase(
+                                ["figure", "letter", "legal", "ledger",
+                                 *[f"{ab}{i}" for ab in "ab" for i in range(11)]]),
     "ps.useafm":          validate_bool,
     # use ghostscript or xpdf to distill ps output
     "ps.usedistiller":    validate_ps_distiller,
diff --git a/lib/matplotlib/table.py b/lib/matplotlib/table.py
index 0f75021926fd..212cd9f45187 100644
--- a/lib/matplotlib/table.py
+++ b/lib/matplotlib/table.py
@@ -496,11 +496,7 @@ def auto_set_column_width(self, col):
         """
         col1d = np.atleast_1d(col)
         if not np.issubdtype(col1d.dtype, np.integer):
-            _api.warn_deprecated("3.8", name="col",
-                                 message="%(name)r must be an int or sequence of ints. "
-                                 "Passing other types is deprecated since %(since)s "
-                                 "and will be removed %(removal)s.")
-            return
+            raise TypeError("col must be an int or sequence of ints.")
         for cell in col1d:
             self._autoColumns.append(cell)
 
diff --git a/lib/matplotlib/tests/test_backend_pdf.py b/lib/matplotlib/tests/test_backend_pdf.py
index 6a6dc1a6bac1..3fcf124e364d 100644
--- a/lib/matplotlib/tests/test_backend_pdf.py
+++ b/lib/matplotlib/tests/test_backend_pdf.py
@@ -81,48 +81,18 @@ def test_multipage_properfinalize():
 
 
 def test_multipage_keep_empty(tmp_path):
-    # test empty pdf files
-
-    # an empty pdf is left behind with keep_empty unset
+    # An empty pdf deletes itself afterwards.
     fn = tmp_path / "a.pdf"
-    with pytest.warns(mpl.MatplotlibDeprecationWarning), PdfPages(fn) as pdf:
-        pass
-    assert fn.exists()
-
-    # an empty pdf is left behind with keep_empty=True
-    fn = tmp_path / "b.pdf"
-    with (pytest.warns(mpl.MatplotlibDeprecationWarning),
-          PdfPages(fn, keep_empty=True) as pdf):
-        pass
-    assert fn.exists()
-
-    # an empty pdf deletes itself afterwards with keep_empty=False
-    fn = tmp_path / "c.pdf"
-    with PdfPages(fn, keep_empty=False) as pdf:
+    with PdfPages(fn) as pdf:
         pass
     assert not fn.exists()
 
-    # test pdf files with content, they should never be deleted
-
-    # a non-empty pdf is left behind with keep_empty unset
-    fn = tmp_path / "d.pdf"
+    # Test pdf files with content, they should never be deleted.
+    fn = tmp_path / "b.pdf"
     with PdfPages(fn) as pdf:
         pdf.savefig(plt.figure())
     assert fn.exists()
 
-    # a non-empty pdf is left behind with keep_empty=True
-    fn = tmp_path / "e.pdf"
-    with (pytest.warns(mpl.MatplotlibDeprecationWarning),
-          PdfPages(fn, keep_empty=True) as pdf):
-        pdf.savefig(plt.figure())
-    assert fn.exists()
-
-    # a non-empty pdf is left behind with keep_empty=False
-    fn = tmp_path / "f.pdf"
-    with PdfPages(fn, keep_empty=False) as pdf:
-        pdf.savefig(plt.figure())
-    assert fn.exists()
-
 
 def test_composite_image():
     # Test that figures can be saved with and without combining multiple images
diff --git a/lib/matplotlib/tests/test_backend_pgf.py b/lib/matplotlib/tests/test_backend_pgf.py
index 54b1c3b5896e..e218a81cdceb 100644
--- a/lib/matplotlib/tests/test_backend_pgf.py
+++ b/lib/matplotlib/tests/test_backend_pgf.py
@@ -288,48 +288,18 @@ def test_pdf_pages_metadata_check(monkeypatch, system):
 
 @needs_pgf_xelatex
 def test_multipage_keep_empty(tmp_path):
-    # test empty pdf files
-
-    # an empty pdf is left behind with keep_empty unset
+    # An empty pdf deletes itself afterwards.
     fn = tmp_path / "a.pdf"
-    with pytest.warns(mpl.MatplotlibDeprecationWarning), PdfPages(fn) as pdf:
-        pass
-    assert fn.exists()
-
-    # an empty pdf is left behind with keep_empty=True
-    fn = tmp_path / "b.pdf"
-    with (pytest.warns(mpl.MatplotlibDeprecationWarning),
-          PdfPages(fn, keep_empty=True) as pdf):
-        pass
-    assert fn.exists()
-
-    # an empty pdf deletes itself afterwards with keep_empty=False
-    fn = tmp_path / "c.pdf"
-    with PdfPages(fn, keep_empty=False) as pdf:
+    with PdfPages(fn) as pdf:
         pass
     assert not fn.exists()
 
-    # test pdf files with content, they should never be deleted
-
-    # a non-empty pdf is left behind with keep_empty unset
-    fn = tmp_path / "d.pdf"
+    # Test pdf files with content, they should never be deleted.
+    fn = tmp_path / "b.pdf"
     with PdfPages(fn) as pdf:
         pdf.savefig(plt.figure())
     assert fn.exists()
 
-    # a non-empty pdf is left behind with keep_empty=True
-    fn = tmp_path / "e.pdf"
-    with (pytest.warns(mpl.MatplotlibDeprecationWarning),
-          PdfPages(fn, keep_empty=True) as pdf):
-        pdf.savefig(plt.figure())
-    assert fn.exists()
-
-    # a non-empty pdf is left behind with keep_empty=False
-    fn = tmp_path / "f.pdf"
-    with PdfPages(fn, keep_empty=False) as pdf:
-        pdf.savefig(plt.figure())
-    assert fn.exists()
-
 
 @needs_pgf_xelatex
 def test_tex_restart_after_error():
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index c587a00c0af9..cc968795802e 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -371,10 +371,10 @@ def test_colorbar_shift(tmp_path):
     plt.colorbar()
 
 
-def test_auto_papersize_deprecation():
+def test_auto_papersize_removal():
     fig = plt.figure()
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
+    with pytest.raises(ValueError, match="'auto' is not a valid value"):
         fig.savefig(io.BytesIO(), format='eps', papertype='auto')
 
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
+    with pytest.raises(ValueError, match="'auto' is not a valid value"):
         mpl.rcParams['ps.papersize'] = 'auto'
diff --git a/lib/matplotlib/tests/test_figure.py b/lib/matplotlib/tests/test_figure.py
index 99045e773d02..528df182a2d0 100644
--- a/lib/matplotlib/tests/test_figure.py
+++ b/lib/matplotlib/tests/test_figure.py
@@ -518,12 +518,10 @@ def test_invalid_figure_add_axes():
         fig.add_axes(ax)
 
     fig2.delaxes(ax)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning,
-                      match="Passing more than one positional argument"):
+    with pytest.raises(TypeError, match=r"add_axes\(\) takes 1 positional arguments"):
         fig2.add_axes(ax, "extra positional argument")
 
-    with pytest.warns(mpl.MatplotlibDeprecationWarning,
-                      match="Passing more than one positional argument"):
+    with pytest.raises(TypeError, match=r"add_axes\(\) takes 1 positional arguments"):
         fig.add_axes([0, 0, 1, 1], "extra positional argument")
 
 
diff --git a/lib/matplotlib/tests/test_legend.py b/lib/matplotlib/tests/test_legend.py
index 62b40ddb2d7a..cf0a950de1ca 100644
--- a/lib/matplotlib/tests/test_legend.py
+++ b/lib/matplotlib/tests/test_legend.py
@@ -19,7 +19,7 @@
 import matplotlib.lines as mlines
 from matplotlib.legend_handler import HandlerTuple
 import matplotlib.legend as mlegend
-from matplotlib import _api, rc_context
+from matplotlib import rc_context
 from matplotlib.font_manager import FontProperties
 
 
@@ -138,19 +138,6 @@ def test_various_labels():
     ax.legend(numpoints=1, loc='best')
 
 
-def test_legend_label_with_leading_underscore():
-    """
-    Test that artists with labels starting with an underscore are not added to
-    the legend, and that a warning is issued if one tries to add them
-    explicitly.
-    """
-    fig, ax = plt.subplots()
-    line, = ax.plot([0, 1], label='_foo')
-    with pytest.warns(_api.MatplotlibDeprecationWarning, match="with an underscore"):
-        legend = ax.legend(handles=[line])
-    assert len(legend.legend_handles) == 0
-
-
 @image_comparison(['legend_labels_first.png'], remove_text=True,
                   tol=0.013 if platform.machine() == 'arm64' else 0)
 def test_labels_first():
diff --git a/lib/matplotlib/tests/test_pyplot.py b/lib/matplotlib/tests/test_pyplot.py
index 63dc239df2e8..21036e177045 100644
--- a/lib/matplotlib/tests/test_pyplot.py
+++ b/lib/matplotlib/tests/test_pyplot.py
@@ -439,9 +439,8 @@ def test_switch_backend_no_close():
     assert len(plt.get_fignums()) == 2
     plt.switch_backend('agg')
     assert len(plt.get_fignums()) == 2
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        plt.switch_backend('svg')
-    assert len(plt.get_fignums()) == 0
+    plt.switch_backend('svg')
+    assert len(plt.get_fignums()) == 2
 
 
 def figure_hook_example(figure):
diff --git a/lib/matplotlib/tests/test_table.py b/lib/matplotlib/tests/test_table.py
index ea31ac124e4a..653e918eecc8 100644
--- a/lib/matplotlib/tests/test_table.py
+++ b/lib/matplotlib/tests/test_table.py
@@ -2,10 +2,8 @@
 from unittest.mock import Mock
 
 import numpy as np
-import pytest
 
 import matplotlib.pyplot as plt
-import matplotlib as mpl
 from matplotlib.path import Path
 from matplotlib.table import CustomCell, Table
 from matplotlib.testing.decorators import image_comparison, check_figures_equal
@@ -128,10 +126,9 @@ def test_customcell():
 
 @image_comparison(['table_auto_column.png'])
 def test_auto_column():
-    fig = plt.figure()
+    fig, (ax1, ax2, ax3, ax4) = plt.subplots(4, 1)
 
     # iterable list input
-    ax1 = fig.add_subplot(4, 1, 1)
     ax1.axis('off')
     tb1 = ax1.table(
         cellText=[['Fit Text', 2],
@@ -144,7 +141,6 @@ def test_auto_column():
     tb1.auto_set_column_width([-1, 0, 1])
 
     # iterable tuple input
-    ax2 = fig.add_subplot(4, 1, 2)
     ax2.axis('off')
     tb2 = ax2.table(
         cellText=[['Fit Text', 2],
@@ -157,7 +153,6 @@ def test_auto_column():
     tb2.auto_set_column_width((-1, 0, 1))
 
     # 3 single inputs
-    ax3 = fig.add_subplot(4, 1, 3)
     ax3.axis('off')
     tb3 = ax3.table(
         cellText=[['Fit Text', 2],
@@ -171,8 +166,8 @@ def test_auto_column():
     tb3.auto_set_column_width(0)
     tb3.auto_set_column_width(1)
 
-    # 4 non integer iterable input
-    ax4 = fig.add_subplot(4, 1, 4)
+    # 4 this used to test non-integer iterable input, which did nothing, but only
+    # remains to avoid re-generating the test image.
     ax4.axis('off')
     tb4 = ax4.table(
         cellText=[['Fit Text', 2],
@@ -182,12 +177,6 @@ def test_auto_column():
         loc="center")
     tb4.auto_set_font_size(False)
     tb4.set_fontsize(12)
-    with pytest.warns(mpl.MatplotlibDeprecationWarning,
-                      match="'col' must be an int or sequence of ints"):
-        tb4.auto_set_column_width("-101")  # type: ignore [arg-type]
-    with pytest.warns(mpl.MatplotlibDeprecationWarning,
-                      match="'col' must be an int or sequence of ints"):
-        tb4.auto_set_column_width(["-101"])  # type: ignore [list-item]
 
 
 def test_table_cells():
diff --git a/lib/matplotlib/tests/test_widgets.py b/lib/matplotlib/tests/test_widgets.py
index 58238cd08af2..585d846944e8 100644
--- a/lib/matplotlib/tests/test_widgets.py
+++ b/lib/matplotlib/tests/test_widgets.py
@@ -3,7 +3,6 @@
 import operator
 from unittest import mock
 
-import matplotlib as mpl
 from matplotlib.backend_bases import MouseEvent
 import matplotlib.colors as mcolors
 import matplotlib.widgets as widgets
@@ -131,16 +130,6 @@ def test_rectangle_minspan(ax, spancoords, minspanx, x1, minspany, y1):
     assert kwargs == {}
 
 
-def test_deprecation_selector_visible_attribute(ax):
-    tool = widgets.RectangleSelector(ax)
-
-    assert tool.get_visible()
-
-    with pytest.warns(mpl.MatplotlibDeprecationWarning,
-                      match="was deprecated in Matplotlib 3.8"):
-        tool.visible
-
-
 @pytest.mark.parametrize('drag_from_anywhere, new_center',
                          [[True, (60, 75)],
                           [False, (30, 20)]])
diff --git a/lib/matplotlib/texmanager.py b/lib/matplotlib/texmanager.py
index 8deb03b3e148..a374bfba8cab 100644
--- a/lib/matplotlib/texmanager.py
+++ b/lib/matplotlib/texmanager.py
@@ -31,7 +31,7 @@
 import numpy as np
 
 import matplotlib as mpl
-from matplotlib import _api, cbook, dviread
+from matplotlib import cbook, dviread
 
 _log = logging.getLogger(__name__)
 
@@ -63,7 +63,6 @@ class TexManager:
     Repeated calls to this constructor always return the same instance.
     """
 
-    texcache = _api.deprecate_privatize_attribute("3.8")
     _texcache = os.path.join(mpl.get_cachedir(), 'tex.cache')
     _grey_arrayd = {}
 
diff --git a/lib/matplotlib/text.py b/lib/matplotlib/text.py
index 6691f32f8771..782dc9754e52 100644
--- a/lib/matplotlib/text.py
+++ b/lib/matplotlib/text.py
@@ -1842,10 +1842,6 @@ def transform(renderer) -> Transform
                 # modified YAArrow API to be used with FancyArrowPatch
                 for key in ['width', 'headwidth', 'headlength', 'shrink']:
                     arrowprops.pop(key, None)
-                if 'frac' in arrowprops:
-                    _api.warn_deprecated(
-                        "3.8", name="the (unused) 'frac' key in 'arrowprops'")
-                    arrowprops.pop("frac")
             self.arrow_patch = FancyArrowPatch((0, 0), (1, 1), **arrowprops)
         else:
             self.arrow_patch = None
diff --git a/lib/matplotlib/transforms.py b/lib/matplotlib/transforms.py
index fde6d6732171..15caff545e73 100644
--- a/lib/matplotlib/transforms.py
+++ b/lib/matplotlib/transforms.py
@@ -93,9 +93,6 @@ class TransformNode:
     # Invalidation may affect only the affine part.  If the
     # invalidation was "affine-only", the _invalid member is set to
     # INVALID_AFFINE_ONLY
-    INVALID_NON_AFFINE = _api.deprecated("3.8")(_api.classproperty(lambda cls: 1))
-    INVALID_AFFINE = _api.deprecated("3.8")(_api.classproperty(lambda cls: 2))
-    INVALID = _api.deprecated("3.8")(_api.classproperty(lambda cls: 3))
 
     # Possible values for the _invalid attribute.
     _VALID, _INVALID_AFFINE_ONLY, _INVALID_FULL = range(3)
@@ -480,7 +477,7 @@ def transformed(self, transform):
              'NW': (0, 1.0),
              'W':  (0, 0.5)}
 
-    def anchored(self, c, container=None):
+    def anchored(self, c, container):
         """
         Return a copy of the `Bbox` anchored to *c* within *container*.
 
@@ -490,19 +487,13 @@ def anchored(self, c, container=None):
             Either an (*x*, *y*) pair of relative coordinates (0 is left or
             bottom, 1 is right or top), 'C' (center), or a cardinal direction
             ('SW', southwest, is bottom left, etc.).
-        container : `Bbox`, optional
+        container : `Bbox`
             The box within which the `Bbox` is positioned.
 
         See Also
         --------
         .Axes.set_anchor
         """
-        if container is None:
-            _api.warn_deprecated(
-                "3.8", message="Calling anchored() with no container bbox "
-                "returns a frozen copy of the original bbox and is deprecated "
-                "since %(since)s.")
-            container = self
         l, b, w, h = container.bounds
         L, B, W, H = self.bounds
         cx, cy = self.coefs[c] if isinstance(c, str) else c
diff --git a/lib/matplotlib/transforms.pyi b/lib/matplotlib/transforms.pyi
index 90a527e5bfc5..c87a965b1e4a 100644
--- a/lib/matplotlib/transforms.pyi
+++ b/lib/matplotlib/transforms.pyi
@@ -77,9 +77,10 @@ class BboxBase(TransformNode):
     def fully_overlaps(self, other: BboxBase) -> bool: ...
     def transformed(self, transform: Transform) -> Bbox: ...
     coefs: dict[str, tuple[float, float]]
-    # anchored type can be s/str/Literal["C", "SW", "S", "SE", "E", "NE", "N", "NW", "W"]
     def anchored(
-        self, c: tuple[float, float] | str, container: BboxBase | None = ...
+        self,
+        c: tuple[float, float] | Literal['C', 'SW', 'S', 'SE', 'E', 'NE', 'N', 'NW', 'W'],
+        container: BboxBase,
     ) -> Bbox: ...
     def shrunk(self, mx: float, my: float) -> Bbox: ...
     def shrunk_to_aspect(
diff --git a/lib/matplotlib/widgets.py b/lib/matplotlib/widgets.py
index 0e8eaa68b6b4..9c676574310c 100644
--- a/lib/matplotlib/widgets.py
+++ b/lib/matplotlib/widgets.py
@@ -2350,11 +2350,6 @@ def get_visible(self):
         """Get the visibility of the selector artists."""
         return self._visible
 
-    @property
-    def visible(self):
-        _api.warn_deprecated("3.8", alternative="get_visible")
-        return self.get_visible()
-
     def clear(self):
         """Clear the selection and set the selector ready to make a new one."""
         self._clear_without_update()
diff --git a/lib/matplotlib/widgets.pyi b/lib/matplotlib/widgets.pyi
index 96bc0c431ac3..0fcd1990e17e 100644
--- a/lib/matplotlib/widgets.pyi
+++ b/lib/matplotlib/widgets.pyi
@@ -294,8 +294,6 @@ class _SelectorWidget(AxesWidget):
     def on_key_release(self, event: Event) -> None: ...
     def set_visible(self, visible: bool) -> None: ...
     def get_visible(self) -> bool: ...
-    @property
-    def visible(self) -> bool: ...
     def clear(self) -> None: ...
     @property
     def artists(self) -> tuple[Artist]: ...
diff --git a/lib/mpl_toolkits/axes_grid1/anchored_artists.py b/lib/mpl_toolkits/axes_grid1/anchored_artists.py
index 1238310b462b..214b15843ebf 100644
--- a/lib/mpl_toolkits/axes_grid1/anchored_artists.py
+++ b/lib/mpl_toolkits/axes_grid1/anchored_artists.py
@@ -1,12 +1,12 @@
-from matplotlib import _api, transforms
+from matplotlib import transforms
 from matplotlib.offsetbox import (AnchoredOffsetbox, AuxTransformBox,
                                   DrawingArea, TextArea, VPacker)
-from matplotlib.patches import (Rectangle, Ellipse, ArrowStyle,
+from matplotlib.patches import (Rectangle, ArrowStyle,
                                 FancyArrowPatch, PathPatch)
 from matplotlib.text import TextPath
 
 __all__ = ['AnchoredDrawingArea', 'AnchoredAuxTransformBox',
-           'AnchoredEllipse', 'AnchoredSizeBar', 'AnchoredDirectionArrows']
+           'AnchoredSizeBar', 'AnchoredDirectionArrows']
 
 
 class AnchoredDrawingArea(AnchoredOffsetbox):
@@ -124,54 +124,6 @@ def __init__(self, transform, loc,
                          **kwargs)
 
 
-@_api.deprecated("3.8")
-class AnchoredEllipse(AnchoredOffsetbox):
-    def __init__(self, transform, width, height, angle, loc,
-                 pad=0.1, borderpad=0.1, prop=None, frameon=True, **kwargs):
-        """
-        Draw an anchored ellipse of a given size.
-
-        Parameters
-        ----------
-        transform : `~matplotlib.transforms.Transform`
-            The transformation object for the coordinate system in use, i.e.,
-            :attr:`matplotlib.axes.Axes.transData`.
-        width, height : float
-            Width and height of the ellipse, given in coordinates of
-            *transform*.
-        angle : float
-            Rotation of the ellipse, in degrees, anti-clockwise.
-        loc : str
-            Location of the ellipse.  Valid locations are
-            'upper left', 'upper center', 'upper right',
-            'center left', 'center', 'center right',
-            'lower left', 'lower center', 'lower right'.
-            For backward compatibility, numeric values are accepted as well.
-            See the parameter *loc* of `.Legend` for details.
-        pad : float, default: 0.1
-            Padding around the ellipse, in fraction of the font size.
-        borderpad : float, default: 0.1
-            Border padding, in fraction of the font size.
-        frameon : bool, default: True
-            If True, draw a box around the ellipse.
-        prop : `~matplotlib.font_manager.FontProperties`, optional
-            Font property used as a reference for paddings.
-        **kwargs
-            Keyword arguments forwarded to `.AnchoredOffsetbox`.
-
-        Attributes
-        ----------
-        ellipse : `~matplotlib.patches.Ellipse`
-            Ellipse patch drawn.
-        """
-        self._box = AuxTransformBox(transform)
-        self.ellipse = Ellipse((0, 0), width, height, angle=angle)
-        self._box.add_artist(self.ellipse)
-
-        super().__init__(loc, pad=pad, borderpad=borderpad, child=self._box,
-                         prop=prop, frameon=frameon, **kwargs)
-
-
 class AnchoredSizeBar(AnchoredOffsetbox):
     def __init__(self, transform, size, label, loc,
                  pad=0.1, borderpad=0.1, sep=2,
diff --git a/lib/mpl_toolkits/axes_grid1/axes_divider.py b/lib/mpl_toolkits/axes_grid1/axes_divider.py
index f6c38f35dbc4..50365f482b72 100644
--- a/lib/mpl_toolkits/axes_grid1/axes_divider.py
+++ b/lib/mpl_toolkits/axes_grid1/axes_divider.py
@@ -199,31 +199,6 @@ def new_locator(self, nx, ny, nx1=None, ny1=None):
         locator.get_subplotspec = self.get_subplotspec
         return locator
 
-    @_api.deprecated(
-        "3.8", alternative="divider.new_locator(...)(ax, renderer)")
-    def locate(self, nx, ny, nx1=None, ny1=None, axes=None, renderer=None):
-        """
-        Implementation of ``divider.new_locator().__call__``.
-
-        Parameters
-        ----------
-        nx, nx1 : int
-            Integers specifying the column-position of the cell. When *nx1* is
-            None, a single *nx*-th column is specified. Otherwise, the
-            location of columns spanning between *nx* to *nx1* (but excluding
-            *nx1*-th column) is specified.
-        ny, ny1 : int
-            Same as *nx* and *nx1*, but for row positions.
-        axes
-        renderer
-        """
-        xref = self._xrefindex
-        yref = self._yrefindex
-        return self._locate(
-            nx - xref, (nx + 1 if nx1 is None else nx1) - xref,
-            ny - yref, (ny + 1 if ny1 is None else ny1) - yref,
-            axes, renderer)
-
     def _locate(self, nx, ny, nx1, ny1, axes, renderer):
         """
         Implementation of ``divider.new_locator().__call__``.
@@ -305,57 +280,6 @@ def add_auto_adjustable_area(self, use_axes, pad=0.1, adjust_dirs=None):
             self.append_size(d, Size._AxesDecorationsSize(use_axes, d) + pad)
 
 
-@_api.deprecated("3.8")
-class AxesLocator:
-    """
-    A callable object which returns the position and size of a given
-    `.AxesDivider` cell.
-    """
-
-    def __init__(self, axes_divider, nx, ny, nx1=None, ny1=None):
-        """
-        Parameters
-        ----------
-        axes_divider : `~mpl_toolkits.axes_grid1.axes_divider.AxesDivider`
-        nx, nx1 : int
-            Integers specifying the column-position of the
-            cell. When *nx1* is None, a single *nx*-th column is
-            specified. Otherwise, location of columns spanning between *nx*
-            to *nx1* (but excluding *nx1*-th column) is specified.
-        ny, ny1 : int
-            Same as *nx* and *nx1*, but for row positions.
-        """
-        self._axes_divider = axes_divider
-
-        _xrefindex = axes_divider._xrefindex
-        _yrefindex = axes_divider._yrefindex
-
-        self._nx, self._ny = nx - _xrefindex, ny - _yrefindex
-
-        if nx1 is None:
-            nx1 = len(self._axes_divider)
-        if ny1 is None:
-            ny1 = len(self._axes_divider[0])
-
-        self._nx1 = nx1 - _xrefindex
-        self._ny1 = ny1 - _yrefindex
-
-    def __call__(self, axes, renderer):
-
-        _xrefindex = self._axes_divider._xrefindex
-        _yrefindex = self._axes_divider._yrefindex
-
-        return self._axes_divider.locate(self._nx + _xrefindex,
-                                         self._ny + _yrefindex,
-                                         self._nx1 + _xrefindex,
-                                         self._ny1 + _yrefindex,
-                                         axes,
-                                         renderer)
-
-    def get_subplotspec(self):
-        return self._axes_divider.get_subplotspec()
-
-
 class SubplotDivider(Divider):
     """
     The Divider class whose rectangle area is specified as a subplot geometry.
diff --git a/lib/mpl_toolkits/axes_grid1/axes_grid.py b/lib/mpl_toolkits/axes_grid1/axes_grid.py
index b5663364481e..20abf18ea79c 100644
--- a/lib/mpl_toolkits/axes_grid1/axes_grid.py
+++ b/lib/mpl_toolkits/axes_grid1/axes_grid.py
@@ -20,11 +20,6 @@ def colorbar(self, mappable, **kwargs):
         return self.get_figure(root=False).colorbar(
             mappable, cax=self, location=self.orientation, **kwargs)
 
-    @_api.deprecated("3.8", alternative="ax.tick_params and colorbar.set_label")
-    def toggle_label(self, b):
-        axis = self.axis[self.orientation]
-        axis.toggle(ticklabels=b, label=b)
-
 
 _cbaraxes_class_factory = cbook._make_class_factory(CbarAxesBase, "Cbar{}")
 
diff --git a/lib/mpl_toolkits/axes_grid1/inset_locator.py b/lib/mpl_toolkits/axes_grid1/inset_locator.py
index 303dbbb0721e..52fe6efc0618 100644
--- a/lib/mpl_toolkits/axes_grid1/inset_locator.py
+++ b/lib/mpl_toolkits/axes_grid1/inset_locator.py
@@ -6,58 +6,13 @@
 from matplotlib.offsetbox import AnchoredOffsetbox
 from matplotlib.patches import Patch, Rectangle
 from matplotlib.path import Path
-from matplotlib.transforms import Bbox, BboxTransformTo
+from matplotlib.transforms import Bbox
 from matplotlib.transforms import IdentityTransform, TransformedBbox
 
 from . import axes_size as Size
 from .parasite_axes import HostAxes
 
 
-@_api.deprecated("3.8", alternative="Axes.inset_axes")
-class InsetPosition:
-    @_docstring.interpd
-    def __init__(self, parent, lbwh):
-        """
-        An object for positioning an inset axes.
-
-        This is created by specifying the normalized coordinates in the axes,
-        instead of the figure.
-
-        Parameters
-        ----------
-        parent : `~matplotlib.axes.Axes`
-            Axes to use for normalizing coordinates.
-
-        lbwh : iterable of four floats
-            The left edge, bottom edge, width, and height of the inset axes, in
-            units of the normalized coordinate of the *parent* axes.
-
-        See Also
-        --------
-        :meth:`matplotlib.axes.Axes.set_axes_locator`
-
-        Examples
-        --------
-        The following bounds the inset axes to a box with 20%% of the parent
-        axes height and 40%% of the width. The size of the axes specified
-        ([0, 0, 1, 1]) ensures that the axes completely fills the bounding box:
-
-        >>> parent_axes = plt.gca()
-        >>> ax_ins = plt.axes([0, 0, 1, 1])
-        >>> ip = InsetPosition(parent_axes, [0.5, 0.1, 0.4, 0.2])
-        >>> ax_ins.set_axes_locator(ip)
-        """
-        self.parent = parent
-        self.lbwh = lbwh
-
-    def __call__(self, ax, renderer):
-        bbox_parent = self.parent.get_position(original=False)
-        trans = BboxTransformTo(bbox_parent)
-        bbox_inset = Bbox.from_bounds(*self.lbwh)
-        bb = TransformedBbox(bbox_inset, trans)
-        return bb
-
-
 class AnchoredLocatorBase(AnchoredOffsetbox):
     def __init__(self, bbox_to_anchor, offsetbox, loc,
                  borderpad=0.5, bbox_transform=None):
diff --git a/lib/mpl_toolkits/axes_grid1/tests/baseline_images/test_axes_grid1/insetposition.png b/lib/mpl_toolkits/axes_grid1/tests/baseline_images/test_axes_grid1/insetposition.png
deleted file mode 100644
index e8676cfd6c95..000000000000
Binary files a/lib/mpl_toolkits/axes_grid1/tests/baseline_images/test_axes_grid1/insetposition.png and /dev/null differ
diff --git a/lib/mpl_toolkits/axes_grid1/tests/test_axes_grid1.py b/lib/mpl_toolkits/axes_grid1/tests/test_axes_grid1.py
index 346fcc1d8f02..778bd9ca04d0 100644
--- a/lib/mpl_toolkits/axes_grid1/tests/test_axes_grid1.py
+++ b/lib/mpl_toolkits/axes_grid1/tests/test_axes_grid1.py
@@ -18,15 +18,14 @@
     host_subplot, make_axes_locatable,
     Grid, AxesGrid, ImageGrid)
 from mpl_toolkits.axes_grid1.anchored_artists import (
-    AnchoredAuxTransformBox, AnchoredDrawingArea, AnchoredEllipse,
+    AnchoredAuxTransformBox, AnchoredDrawingArea,
     AnchoredDirectionArrows, AnchoredSizeBar)
 from mpl_toolkits.axes_grid1.axes_divider import (
     Divider, HBoxDivider, make_axes_area_auto_adjustable, SubplotDivider,
     VBoxDivider)
 from mpl_toolkits.axes_grid1.axes_rgb import RGBAxes
 from mpl_toolkits.axes_grid1.inset_locator import (
-    zoomed_inset_axes, mark_inset, inset_axes, BboxConnectorPatch,
-    InsetPosition)
+    zoomed_inset_axes, mark_inset, inset_axes, BboxConnectorPatch)
 import mpl_toolkits.axes_grid1.mpl_axes
 import pytest
 
@@ -543,12 +542,14 @@ def test_anchored_artists():
     box.drawing_area.add_artist(el)
     ax.add_artist(box)
 
-    # Manually construct the ellipse instead, once the deprecation elapses.
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        ae = AnchoredEllipse(ax.transData, width=0.1, height=0.25, angle=-60,
-                             loc='lower left', pad=0.5, borderpad=0.4,
-                             frameon=True)
-    ax.add_artist(ae)
+    # This block used to test the AnchoredEllipse class, but that was removed. The block
+    # remains, though it duplicates the above ellipse, so that the test image doesn't
+    # need to be regenerated.
+    box = AnchoredAuxTransformBox(ax.transData, loc='lower left', frameon=True,
+                                  pad=0.5, borderpad=0.4)
+    el = Ellipse((0, 0), width=0.1, height=0.25, angle=-60)
+    box.drawing_area.add_artist(el)
+    ax.add_artist(box)
 
     asb = AnchoredSizeBar(ax.transData, 0.2, r"0.2 units", loc='lower right',
                           pad=0.3, borderpad=0.4, sep=4, fill_bar=True,
@@ -702,17 +703,6 @@ def test_rgb_axes():
     ax.imshow_rgb(r, g, b, interpolation='none')
 
 
-# Update style when regenerating the test image
-@image_comparison(['insetposition.png'], remove_text=True,
-                  style=('classic', '_classic_test_patch'))
-def test_insetposition():
-    fig, ax = plt.subplots(figsize=(2, 2))
-    ax_ins = plt.axes([0, 0, 1, 1])
-    with pytest.warns(mpl.MatplotlibDeprecationWarning):
-        ip = InsetPosition(ax, [0.2, 0.25, 0.5, 0.4])
-    ax_ins.set_axes_locator(ip)
-
-
 # The original version of this test relied on mpl_toolkits's slightly different
 # colorbar implementation; moving to matplotlib's own colorbar implementation
 # caused the small image comparison error.
diff --git a/lib/mpl_toolkits/axisartist/axes_divider.py b/lib/mpl_toolkits/axisartist/axes_divider.py
index a01d4e27df93..d0392be782d9 100644
--- a/lib/mpl_toolkits/axisartist/axes_divider.py
+++ b/lib/mpl_toolkits/axisartist/axes_divider.py
@@ -1,2 +1,2 @@
 from mpl_toolkits.axes_grid1.axes_divider import (  # noqa
-    Divider, AxesLocator, SubplotDivider, AxesDivider, make_axes_locatable)
+    Divider, SubplotDivider, AxesDivider, make_axes_locatable)
diff --git a/lib/mpl_toolkits/axisartist/axes_grid.py b/lib/mpl_toolkits/axisartist/axes_grid.py
deleted file mode 100644
index ecb3e9d92c18..000000000000
--- a/lib/mpl_toolkits/axisartist/axes_grid.py
+++ /dev/null
@@ -1,23 +0,0 @@
-from matplotlib import _api
-
-import mpl_toolkits.axes_grid1.axes_grid as axes_grid_orig
-from .axislines import Axes
-
-
-_api.warn_deprecated(
-    "3.8", name=__name__, obj_type="module", alternative="axes_grid1.axes_grid")
-
-
-@_api.deprecated("3.8", alternative=(
-    "axes_grid1.axes_grid.Grid(..., axes_class=axislines.Axes"))
-class Grid(axes_grid_orig.Grid):
-    _defaultAxesClass = Axes
-
-
-@_api.deprecated("3.8", alternative=(
-    "axes_grid1.axes_grid.ImageGrid(..., axes_class=axislines.Axes"))
-class ImageGrid(axes_grid_orig.ImageGrid):
-    _defaultAxesClass = Axes
-
-
-AxesGrid = ImageGrid
diff --git a/lib/mpl_toolkits/axisartist/axes_rgb.py b/lib/mpl_toolkits/axisartist/axes_rgb.py
deleted file mode 100644
index 2195747469a1..000000000000
--- a/lib/mpl_toolkits/axisartist/axes_rgb.py
+++ /dev/null
@@ -1,18 +0,0 @@
-from matplotlib import _api
-from mpl_toolkits.axes_grid1.axes_rgb import (  # noqa
-    make_rgb_axes, RGBAxes as _RGBAxes)
-from .axislines import Axes
-
-
-_api.warn_deprecated(
-    "3.8", name=__name__, obj_type="module", alternative="axes_grid1.axes_rgb")
-
-
-@_api.deprecated("3.8", alternative=(
-    "axes_grid1.axes_rgb.RGBAxes(..., axes_class=axislines.Axes"))
-class RGBAxes(_RGBAxes):
-    """
-    Subclass of `~.axes_grid1.axes_rgb.RGBAxes` with
-    ``_defaultAxesClass`` = `.axislines.Axes`.
-    """
-    _defaultAxesClass = Axes
diff --git a/lib/mpl_toolkits/axisartist/axislines.py b/lib/mpl_toolkits/axisartist/axislines.py
index 1d695c129ae2..8d06cb236269 100644
--- a/lib/mpl_toolkits/axisartist/axislines.py
+++ b/lib/mpl_toolkits/axisartist/axislines.py
@@ -370,10 +370,6 @@ def get_gridlines(self, which="major", axis="both"):
 
 class Axes(maxes.Axes):
 
-    @_api.deprecated("3.8", alternative="ax.axis")
-    def __call__(self, *args, **kwargs):
-        return maxes.Axes.axis(self.axes, *args, **kwargs)
-
     def __init__(self, *args, grid_helper=None, **kwargs):
         self._axisline_on = True
         self._grid_helper = grid_helper if grid_helper else GridHelperRectlinear(self)
diff --git a/lib/mpl_toolkits/axisartist/floating_axes.py b/lib/mpl_toolkits/axisartist/floating_axes.py
index ecdcca5122bf..74e4c941879b 100644
--- a/lib/mpl_toolkits/axisartist/floating_axes.py
+++ b/lib/mpl_toolkits/axisartist/floating_axes.py
@@ -147,17 +147,6 @@ def __init__(self, aux_trans, extremes,
                          tick_formatter1=tick_formatter1,
                          tick_formatter2=tick_formatter2)
 
-    @_api.deprecated("3.8")
-    def get_data_boundary(self, side):
-        """
-        Return v=0, nth=1.
-        """
-        lon1, lon2, lat1, lat2 = self.grid_finder.extreme_finder(*[None] * 5)
-        return dict(left=(lon1, 0),
-                    right=(lon2, 0),
-                    bottom=(lat1, 1),
-                    top=(lat2, 1))[side]
-
     def new_fixed_axis(
             self, loc, nth_coord=None, axis_direction=None, offset=None, axes=None):
         if axes is None:
diff --git a/lib/mpl_toolkits/axisartist/meson.build b/lib/mpl_toolkits/axisartist/meson.build
index 8d9314e42576..6d95cf0dfdcd 100644
--- a/lib/mpl_toolkits/axisartist/meson.build
+++ b/lib/mpl_toolkits/axisartist/meson.build
@@ -2,8 +2,6 @@ python_sources = [
   '__init__.py',
   'angle_helper.py',
   'axes_divider.py',
-  'axes_grid.py',
-  'axes_rgb.py',
   'axis_artist.py',
   'axislines.py',
   'axisline_style.py',
diff --git a/lib/mpl_toolkits/mplot3d/axis3d.py b/lib/mpl_toolkits/mplot3d/axis3d.py
index 0562b421e22c..4da5031b990c 100644
--- a/lib/mpl_toolkits/mplot3d/axis3d.py
+++ b/lib/mpl_toolkits/mplot3d/axis3d.py
@@ -195,11 +195,6 @@ def set_ticks_position(self, position):
         position : {'lower', 'upper', 'both', 'default', 'none'}
             The position of the bolded axis lines, ticks, and tick labels.
         """
-        if position in ['top', 'bottom']:
-            _api.warn_deprecated('3.8', name=f'{position=}',
-                                 obj_type='argument value',
-                                 alternative="'upper' or 'lower'")
-            return
         _api.check_in_list(['lower', 'upper', 'both', 'default', 'none'],
                            position=position)
         self._tick_position = position
@@ -224,11 +219,6 @@ def set_label_position(self, position):
         position : {'lower', 'upper', 'both', 'default', 'none'}
             The position of the axis label.
         """
-        if position in ['top', 'bottom']:
-            _api.warn_deprecated('3.8', name=f'{position=}',
-                                 obj_type='argument value',
-                                 alternative="'upper' or 'lower'")
-            return
         _api.check_in_list(['lower', 'upper', 'both', 'default', 'none'],
                            position=position)
         self._label_position = position