diff --git a/README.rst b/README.rst
@@ -8,48 +8,12 @@ Python C API compatibility
 
 The ``pythoncapi-compat`` project can be used to write a C or C++ extension
 supporting a wide range of Python versions with a single code base.  It is made
-of the ``pythoncapi_compat.h`` header file and the ``upgrade_pythoncapi.py``
-script.
-
-``upgrade_pythoncapi.py`` requires Python 3.6 or newer.
+of the ``pythoncapi_compat.h`` header file.
 
 See the `documentation at ReadTheDocs
 <https://pythoncapi-compat.readthedocs.io/en/latest/>`_
 for more details.
 
-Getting started
-===============
-
-To upgrade a specific file::
-
-    python3 upgrade_pythoncapi.py module.c
-
-To upgrade all C/C++ files in a directory::
-
-    python3 upgrade_pythoncapi.py src/
-
-Select operations
------------------
-
-To only replace ``op->ob_type`` with ``Py_TYPE(op)``, select the ``Py_TYPE``
-operation with::
-
-    python3 upgrade_pythoncapi.py -o Py_TYPE module.c
-
-Or the opposite, to apply all operations but leave ``op->ob_type`` unchanged,
-deselect the ``Py_TYPE`` operation with::
-
-    python3 upgrade_pythoncapi.py -o all,-Py_TYPE module.c
-
-Download pythoncapi_compat.h
-----------------------------
-
-If you want to ``pythoncapi_compat.h`` to your code base, use the
-``upgrade_pythoncapi.py`` tool to fetch it::
-
-    python3 upgrade_pythoncapi.py --download PATH
-
-
 This project is distributed under the `Zero Clause BSD (0BSD) license
 <https://opensource.org/licenses/0BSD>`_ and is covered by the `PSF Code of
 Conduct <https://www.python.org/psf/codeofconduct/>`_.
diff --git a/docs/changelog.rst b/docs/changelog.rst
@@ -1,6 +1,7 @@
 Changelog
 =========
 
+* 2026-10-11: Remove the ``upgrade_pythoncapi.py`` script.
 * 2026-10-10: Add ``PyObject_GenericHash()`` and
   ``PyUnicodeWriter_WriteUCS4()`` functions. runtests.py now runs tests in
   parallel.

diff --git a/docs/index.rst b/docs/index.rst
@@ -4,8 +4,7 @@ Python C API compatibility
 
 The ``pythoncapi-compat`` project can be used to write a C or C++ extension
 supporting a wide range of Python versions with a single code base.  It is made
-of the ``pythoncapi_compat.h`` header file and the ``upgrade_pythoncapi.py``
-script.
+of the ``pythoncapi_compat.h`` header file.
 
 * Homepage: `GitHub pythoncapi-compat project
   <https://github.com/python/pythoncapi-compat>`_.
@@ -18,7 +17,6 @@ Documentation:
    :maxdepth: 2
 
    api
-   upgrade
    users
    tests
    changelog

diff --git a/docs/upgrade.rst b/docs/upgrade.rst
diff --git a/runtests.py b/runtests.py
@@ -20,7 +20,6 @@
 
 TEST_DIR = os.path.join(os.path.dirname(__file__), 'tests')
 TEST_COMPAT = os.path.join(TEST_DIR, "test_pythoncapi_compat.py")
-TEST_UPGRADE = os.path.join(TEST_DIR, "test_upgrade_pythoncapi.py")
 
 PYTHONS = (
     # CPython
@@ -123,16 +122,6 @@ def worker(executable):
     print(f"Tested: {len(jobs)} Python executables")
 
 
-def test_upgrade_pythoncapi(args):
-    # upgrade_pythoncapi.py requires Python 3.6 or newer
-    print(f"Run {TEST_UPGRADE}")
-    cmd = [sys.executable, "-u", TEST_UPGRADE]
-    if args.verbose:
-        cmd.append('-v')
-    run_command(cmd)
-    print()
-
-
 def test_current_version(args):
     with tempfile.TemporaryDirectory() as build_dir:
         cmd = get_test_command(sys.executable, args.verbose, build_dir)
@@ -144,8 +133,6 @@ def main():
     start_time = time.perf_counter()
     args = parse_args()
 
-    test_upgrade_pythoncapi(args)
-
     if not args.current:
         run_tests_parallel(args)
     else: