diff --git a/CHANGES b/CHANGES
index 931c0e0dcdd..1985b74c434 100644
--- a/CHANGES
+++ b/CHANGES
@@ -13,6 +13,7 @@ Deprecated
 Features added
 --------------
 
+* #10133: autodoc: Crashed when mocked module is used for type annotation
 * #9494, #9456: html search: Add a config variable
   :confval:`html_show_search_summary` to enable/disable the search summaries
 
diff --git a/sphinx/ext/autodoc/mock.py b/sphinx/ext/autodoc/mock.py
index 36b2836f3e2..7bd0b1ea017 100644
--- a/sphinx/ext/autodoc/mock.py
+++ b/sphinx/ext/autodoc/mock.py
@@ -154,6 +154,11 @@ def mock(modnames: List[str]) -> Generator[None, None, None]:
         finder.invalidate_caches()
 
 
+def ismockmodule(subject: Any) -> bool:
+    """Check if the object is a mocked module."""
+    return isinstance(subject, _MockModule)
+
+
 def ismock(subject: Any) -> bool:
     """Check if the object is mocked."""
     # check the object has '__sphinx_mock__' attribute
diff --git a/sphinx/util/typing.py b/sphinx/util/typing.py
index d9b63e046e3..5cd0c230ef2 100644
--- a/sphinx/util/typing.py
+++ b/sphinx/util/typing.py
@@ -116,6 +116,7 @@ def restify(cls: Optional[Type], mode: str = 'fully-qualified-except-typing') ->
                  'smart'
                      Show the name of the annotation.
     """
+    from sphinx.ext.autodoc.mock import ismock, ismockmodule  # lazy loading
     from sphinx.util import inspect  # lazy loading
 
     if mode == 'smart':
@@ -130,6 +131,10 @@ def restify(cls: Optional[Type], mode: str = 'fully-qualified-except-typing') ->
             return '...'
         elif isinstance(cls, str):
             return cls
+        elif ismockmodule(cls):
+            return ':py:class:`%s%s`' % (modprefix, cls.__name__)
+        elif ismock(cls):
+            return ':py:class:`%s%s.%s`' % (modprefix, cls.__module__, cls.__name__)
         elif cls in INVALID_BUILTIN_CLASSES:
             return ':py:class:`%s%s`' % (modprefix, INVALID_BUILTIN_CLASSES[cls])
         elif inspect.isNewType(cls):
@@ -335,6 +340,7 @@ def stringify(annotation: Any, mode: str = 'fully-qualified-except-typing') -> s
                  'fully-qualified'
                      Show the module name and qualified name of the annotation.
     """
+    from sphinx.ext.autodoc.mock import ismock, ismockmodule  # lazy loading
     from sphinx.util import inspect  # lazy loading
 
     if mode == 'smart':
@@ -364,6 +370,10 @@ def stringify(annotation: Any, mode: str = 'fully-qualified-except-typing') -> s
         return repr(annotation)
     elif annotation is NoneType:
         return 'None'
+    elif ismockmodule(annotation):
+        return modprefix + annotation.__name__
+    elif ismock(annotation):
+        return modprefix + '%s.%s' % (annotation.__module__, annotation.__name__)
     elif annotation in INVALID_BUILTIN_CLASSES:
         return modprefix + INVALID_BUILTIN_CLASSES[annotation]
     elif str(annotation).startswith('typing.Annotated'):  # for py310+
diff --git a/tests/test_util_typing.py b/tests/test_util_typing.py
index c061fa08518..7d81fee5d7b 100644
--- a/tests/test_util_typing.py
+++ b/tests/test_util_typing.py
@@ -213,6 +213,7 @@ def test_restify_broken_type_hints():
 def test_restify_mock():
     with mock(['unknown']):
         import unknown
+        assert restify(unknown) == ':py:class:`unknown`'
         assert restify(unknown.secret.Class) == ':py:class:`unknown.secret.Class`'
         assert restify(unknown.secret.Class, "smart") == ':py:class:`~unknown.secret.Class`'
 
@@ -480,5 +481,6 @@ def test_stringify_broken_type_hints():
 def test_stringify_mock():
     with mock(['unknown']):
         import unknown
+        assert stringify(unknown) == 'unknown'
         assert stringify(unknown.secret.Class) == 'unknown.secret.Class'
         assert stringify(unknown.secret.Class, "smart") == 'unknown.secret.Class'