diff --git a/Lib/argparse.py b/Lib/argparse.py
index d1f8fa2ace8611..9399e0e2f68819 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -1997,7 +1997,7 @@ def consume_optional(start_index):
             if len(option_tuples) > 1:
                 options = ', '.join([option_string
                     for action, option_string, sep, explicit_arg in option_tuples])
-                args = {'option': arg_string, 'matches': options}
+                args = {'option': arg_strings[start_index], 'matches': options}
                 msg = _('ambiguous option: %(option)s could match %(matches)s')
                 raise ArgumentError(None, msg % args)
 
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
index c9e79eb18a08fb..58cc0fe86b450a 100644
--- a/Lib/test/test_argparse.py
+++ b/Lib/test/test_argparse.py
@@ -6669,9 +6669,19 @@ def test_conflicting_mutually_exclusive_args_zero_or_more_with_metavar2(self):
     def test_ambiguous_option(self):
         self.parser.add_argument('--foobaz')
         self.parser.add_argument('--fooble', action='store_true')
+        self.parser.add_argument('--foogle')
         self.assertRaisesRegex(argparse.ArgumentError,
-                               "ambiguous option: --foob could match --foobaz, --fooble",
-                               self.parser.parse_args, ['--foob'])
+                "ambiguous option: --foob could match --foobaz, --fooble",
+            self.parser.parse_args, ['--foob'])
+        self.assertRaisesRegex(argparse.ArgumentError,
+                "ambiguous option: --foob=1 could match --foobaz, --fooble$",
+            self.parser.parse_args, ['--foob=1'])
+        self.assertRaisesRegex(argparse.ArgumentError,
+                "ambiguous option: --foob could match --foobaz, --fooble$",
+            self.parser.parse_args, ['--foob', '1', '--foogle', '2'])
+        self.assertRaisesRegex(argparse.ArgumentError,
+                "ambiguous option: --foob=1 could match --foobaz, --fooble$",
+            self.parser.parse_args, ['--foob=1', '--foogle', '2'])
 
     def test_os_error(self):
         self.parser.add_argument('file')
diff --git a/Misc/NEWS.d/next/Library/2024-10-10-19-57-35.gh-issue-125254.RtZxXS.rst b/Misc/NEWS.d/next/Library/2024-10-10-19-57-35.gh-issue-125254.RtZxXS.rst
new file mode 100644
index 00000000000000..abe37fefedc3be
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2024-10-10-19-57-35.gh-issue-125254.RtZxXS.rst
@@ -0,0 +1 @@
+Fix a bug where ArgumentError includes the incorrect ambiguous option in :mod:`argparse`.