diff --git a/CHANGES b/CHANGES
index e4f45c12f..6434cc3a7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -62,7 +62,8 @@ Deprecated
 * ``sphinx.testing.util.remove_unicode_literal()``
 * ``sphinx.util.attrdict``
 * ``sphinx.util.force_decode()``
-* ``sphinx.util.get_matching_docs()`` is deprecated
+* ``sphinx.util.get_matching_docs()``
+* ``sphinx.util.inspect.Parameter``
 * ``sphinx.util.osutil.walk()``
 * ``sphinx.util.PeekableIterator``
 * ``sphinx.util.pycompat.u``
diff --git a/doc/extdev/index.rst b/doc/extdev/index.rst
index 4dc9f9480..003666217 100644
--- a/doc/extdev/index.rst
+++ b/doc/extdev/index.rst
@@ -202,6 +202,11 @@ The following is a list of deprecated interfaces.
      - 4.0
      - ``sphinx.util.get_matching_files()``
 
+   * - ``sphinx.util.inspect.Parameter``
+     - 2.0
+     - 3.0
+     - N/A
+
    * - ``sphinx.util.osutil.walk()``
      - 2.0
      - 4.0
diff --git a/sphinx/util/inspect.py b/sphinx/util/inspect.py
index eeedf77ab..eebcbc7b8 100644
--- a/sphinx/util/inspect.py
+++ b/sphinx/util/inspect.py
@@ -16,10 +16,12 @@ import inspect
 import re
 import sys
 import typing
+import warnings
 from functools import partial
 
 from six import StringIO
 
+from sphinx.deprecation import RemovedInSphinx30Warning
 from sphinx.util import logging
 from sphinx.util.pycompat import NoneType
 
@@ -289,6 +291,9 @@ class Parameter:
         self.default = default
         self.annotation = self.empty
 
+        warnings.warn('sphinx.util.inspect.Parameter is deprecated.',
+                      RemovedInSphinx30Warning, stacklevel=2)
+
 
 class Signature:
     """The Signature object represents the call signature of a callable object and