diff --git a/django/test/signals.py b/django/test/signals.py
index e531cd72f5..cb78b76114 100644
--- a/django/test/signals.py
+++ b/django/test/signals.py
@@ -202,6 +202,14 @@ def static_finders_changed(*, setting, **kwargs):
         get_finder.cache_clear()
 
 
+@receiver(setting_changed)
+def form_renderer_changed(*, setting, **kwargs):
+    if setting == "FORM_RENDERER":
+        from django.forms.renderers import get_default_renderer
+
+        get_default_renderer.cache_clear()
+
+
 @receiver(setting_changed)
 def auth_password_validators_changed(*, setting, **kwargs):
     if setting == "AUTH_PASSWORD_VALIDATORS":
diff --git a/docs/topics/testing/tools.txt b/docs/topics/testing/tools.txt
index 89c914a864..4eaffdb331 100644
--- a/docs/topics/testing/tools.txt
+++ b/docs/topics/testing/tools.txt
@@ -1502,11 +1502,17 @@ Overridden settings               Data reset
 ================================= ========================
 USE_TZ, TIME_ZONE                 Databases timezone
 TEMPLATES                         Template engines
+FORM_RENDERER                     Default renderer
 SERIALIZATION_MODULES             Serializers cache
 LOCALE_PATHS, LANGUAGE_CODE       Default translation and loaded translations
 STATIC_ROOT, STATIC_URL, STORAGES Storages configuration
 ================================= ========================
 
+.. versionchanged:: 5.1
+
+    Resetting the default renderer when the ``FORM_RENDERER`` setting is
+    changed was added.
+
 Isolating apps
 --------------
 
diff --git a/tests/forms_tests/tests/test_forms.py b/tests/forms_tests/tests/test_forms.py
index 547f58632f..877571726d 100644
--- a/tests/forms_tests/tests/test_forms.py
+++ b/tests/forms_tests/tests/test_forms.py
@@ -5145,7 +5145,6 @@ class OverrideTests(SimpleTestCase):
         class Person(Form):
             first_name = CharField()
 
-        get_default_renderer.cache_clear()
         t = Template("{{ form }}")
         html = t.render(Context({"form": Person()}))
         expected = """
@@ -5153,14 +5152,12 @@ class OverrideTests(SimpleTestCase):
         <input type="text" name="first_name" required id="id_first_name"></div>
         """
         self.assertHTMLEqual(html, expected)
-        get_default_renderer.cache_clear()
 
     @override_settings(FORM_RENDERER="forms_tests.tests.test_forms.CustomRenderer")
     def test_custom_renderer_field_template_name(self):
         class Person(Form):
             first_name = CharField()
 
-        get_default_renderer.cache_clear()
         t = Template("{{ form.first_name.as_field_group }}")
         html = t.render(Context({"form": Person()}))
         expected = """
@@ -5169,7 +5166,6 @@ class OverrideTests(SimpleTestCase):
         <input type="text" name="first_name" required id="id_first_name">
         """
         self.assertHTMLEqual(html, expected)
-        get_default_renderer.cache_clear()
 
     def test_per_form_template_name(self):
         class Person(Form):
diff --git a/tests/template_tests/test_autoreloader.py b/tests/template_tests/test_autoreloader.py
index 2336f4e6f8..1eac0a54d6 100644
--- a/tests/template_tests/test_autoreloader.py
+++ b/tests/template_tests/test_autoreloader.py
@@ -1,7 +1,6 @@
 from pathlib import Path
 from unittest import mock
 
-from django.forms.renderers import get_default_renderer
 from django.template import autoreload
 from django.test import SimpleTestCase, override_settings
 from django.test.utils import require_jinja2
@@ -74,8 +73,6 @@ class TemplateReloadTests(SimpleTestCase):
     def test_form_template_reset_template_change_no_djangotemplates(
         self, mock_loader_reset
     ):
-        self.addCleanup(get_default_renderer.cache_clear)
-        get_default_renderer.cache_clear()
         template_path = Path(__file__).parent / "templates" / "index.html"
         self.assertIs(autoreload.template_changed(None, template_path), True)
         mock_loader_reset.assert_not_called()