diff --git a/Lib/shutil.py b/Lib/shutil.py
index 03a9d756030430..65ac4f31f3efb1 100644
--- a/Lib/shutil.py
+++ b/Lib/shutil.py
@@ -44,7 +44,7 @@
 else:
     _winapi = None
 
-COPY_BUFSIZE = 1024 * 1024 if _WINDOWS else 64 * 1024
+COPY_BUFSIZE = 1024 * 1024 if _WINDOWS else 256 * 1024
 # This should never be removed, see rationale in:
 # https://bugs.python.org/issue43743#msg393429
 _USE_CP_SENDFILE = (hasattr(os, "sendfile")
diff --git a/Misc/NEWS.d/next/Library/2024-10-03-05-00-25.gh-issue-117151.Prdw_W.rst b/Misc/NEWS.d/next/Library/2024-10-03-05-00-25.gh-issue-117151.Prdw_W.rst
new file mode 100644
index 00000000000000..a7d6251f1e071f
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-10-03-05-00-25.gh-issue-117151.Prdw_W.rst
@@ -0,0 +1,3 @@
+The default buffer size used by :func:`shutil.copyfileobj` has been
+increased from 64k to 256k on non-Windows platforms. It was already larger
+on Windows.