diff --git a/django/contrib/auth/middleware.py b/django/contrib/auth/middleware.py
index df4c0d41da..bd8a1c1080 100644
--- a/django/contrib/auth/middleware.py
+++ b/django/contrib/auth/middleware.py
@@ -1,8 +1,7 @@
-import warnings
 from functools import partial
 from urllib.parse import urlsplit
 
-from asgiref.sync import iscoroutinefunction, markcoroutinefunction, sync_to_async
+from asgiref.sync import iscoroutinefunction, markcoroutinefunction
 
 from django.conf import settings
 from django.contrib import auth
@@ -11,7 +10,7 @@ from django.contrib.auth.backends import RemoteUserBackend
 from django.contrib.auth.views import redirect_to_login
 from django.core.exceptions import ImproperlyConfigured
 from django.shortcuts import resolve_url
-from django.utils.deprecation import MiddlewareMixin, RemovedInDjango61Warning
+from django.utils.deprecation import MiddlewareMixin
 from django.utils.functional import SimpleLazyObject
 
 
@@ -172,20 +171,6 @@ class RemoteUserMiddleware:
             auth.login(request, user)
 
     async def __acall__(self, request):
-        # RemovedInDjango61Warning.
-        if (
-            self.__class__.process_request is not RemoteUserMiddleware.process_request
-            and self.__class__.aprocess_request is RemoteUserMiddleware.aprocess_request
-        ):
-            warnings.warn(
-                "Support for subclasses of RemoteUserMiddleware that override "
-                "process_request() without overriding aprocess_request() is "
-                "deprecated.",
-                category=RemovedInDjango61Warning,
-                stacklevel=2,
-            )
-            await sync_to_async(self.process_request, thread_sensitive=True)(request)
-            return await self.get_response(request)
         await self.aprocess_request(request)
         return await self.get_response(request)
 
diff --git a/docs/releases/6.1.txt b/docs/releases/6.1.txt
index 5b98cda2a6..70da3ade6a 100644
--- a/docs/releases/6.1.txt
+++ b/docs/releases/6.1.txt
@@ -278,3 +278,7 @@ to remove usage of these features.
   ``django.contrib.postgres.aggregates.JSONBAgg``, and
   ``django.contrib.postgres.aggregates.StringAgg`` are removed in favor
   of the ``order_by`` parameter.
+
+* Support for subclasses of ``RemoteUserMiddleware`` that override
+  ``process_request()`` without overriding ``aprocess_request()`` is
+  removed.
diff --git a/tests/auth_tests/test_remote_user.py b/tests/auth_tests/test_remote_user.py
index c871ea7dc8..4a97fc2120 100644
--- a/tests/auth_tests/test_remote_user.py
+++ b/tests/auth_tests/test_remote_user.py
@@ -13,7 +13,6 @@ from django.test import (
     modify_settings,
     override_settings,
 )
-from django.utils.deprecation import RemovedInDjango61Warning
 
 
 @override_settings(ROOT_URLCONF="auth_tests.urls")
@@ -490,51 +489,3 @@ class PersistentRemoteUserTest(RemoteUserTest):
         response = await self.async_client.get("/remote_user/")
         self.assertFalse(response.context["user"].is_anonymous)
         self.assertEqual(response.context["user"].username, "knownuser")
-
-
-# RemovedInDjango61Warning.
-class CustomProcessRequestMiddlewareSyncOnly(RemoteUserMiddleware):
-    def process_request(self, request):
-        raise NotImplementedError("process_request has not been implemented.")
-
-
-# RemovedInDjango61Warning.
-class CustomProcessRequestMiddleware(RemoteUserMiddleware):
-    def process_request(self, request):
-        raise NotImplementedError("process_request has not been implemented.")
-
-    async def aprocess_request(self, request):
-        raise NotImplementedError("aprocess_request has not been implemented.")
-
-
-# RemovedInDjango61Warning.
-@override_settings(ROOT_URLCONF="auth_tests.urls")
-class CustomProcessRequestMiddlewareTest(TestCase):
-    @modify_settings(
-        MIDDLEWARE={
-            "append": "auth_tests.test_remote_user."
-            "CustomProcessRequestMiddlewareSyncOnly"
-        }
-    )
-    async def test_async_warns_sync_only_middleware(self):
-        deprecation_msg = (
-            "Support for subclasses of RemoteUserMiddleware that override "
-            "process_request() without overriding aprocess_request() is "
-            "deprecated."
-        )
-        error_msg = "process_request has not been implemented."
-        with (
-            self.assertWarnsMessage(RemovedInDjango61Warning, deprecation_msg),
-            self.assertRaisesMessage(NotImplementedError, error_msg),
-        ):
-            await self.async_client.get("/remote_user/")
-
-    @modify_settings(
-        MIDDLEWARE={
-            "append": "auth_tests.test_remote_user.CustomProcessRequestMiddleware"
-        }
-    )
-    async def test_async_no_warning_sync_and_async_middleware(self):
-        error_msg = "aprocess_request has not been implemented."
-        with self.assertRaisesMessage(NotImplementedError, error_msg):
-            await self.async_client.get("/remote_user/")