diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 8629f44f79e157f2f3891def04b1196e83665b02..0becb4ef6863de120341b327691825d0378142aa 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -87,13 +87,20 @@
  * @return array|\Drupal\Core\Utility\ThemeRegistry
  *   The complete theme registry array, or an instance of the
  *   Drupal\Core\Utility\ThemeRegistry class.
+ *
+ * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
+ *   theme.registry service methods get() or getRuntime() instead.
+ *
+ * @see https://www.drupal.org/node/3348850
  */
 function theme_get_registry($complete = TRUE) {
   $theme_registry = \Drupal::service('theme.registry');
   if ($complete) {
+    @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service method get() instead. See https://www.drupal.org/node/3348850', E_USER_DEPRECATED);
     return $theme_registry->get();
   }
   else {
+    @trigger_error(__FUNCTION__ . '() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service method getRuntime() instead. See https://www.drupal.org/node/3348850', E_USER_DEPRECATED);
     return $theme_registry->getRuntime();
   }
 }
diff --git a/core/lib/Drupal/Core/Render/theme.api.php b/core/lib/Drupal/Core/Render/theme.api.php
index 8e77a9c95e7e6423766e052b71e8e7f8425a009e..cb960152278ad64531f71edfef6925ddf8bc5db5 100644
--- a/core/lib/Drupal/Core/Render/theme.api.php
+++ b/core/lib/Drupal/Core/Render/theme.api.php
@@ -547,7 +547,7 @@ function hook_preprocess(&$variables, $hook) {
   }
 
   if (!isset($hooks)) {
-    $hooks = theme_get_registry();
+    $hooks = \Drupal::service('theme.registry')->get();
   }
 
   // Determine the primary theme function argument.
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php b/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php
index 761c785384a32c8c32ab705d66a4b4f7b43558aa..c4669370b2b7e49a2f524e59b363e723980b3dbd 100644
--- a/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Theme/RegistryTest.php
@@ -272,4 +272,18 @@ public function testLegacyThemeRegistryRebuild() {
     $this->assertSame($hooks, $registry->get());
   }
 
+  /**
+   * Tests deprecated theme_get_registry function.
+   *
+   * @see theme_get_registry()
+   * @group legacy
+   */
+  public function testLegacyThemeGetRegistry() {
+    $registry = \Drupal::service('theme.registry');
+    $this->expectDeprecation('theme_get_registry() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service method get() instead. See https://www.drupal.org/node/3348850');
+    $this->assertEquals($registry->get(), theme_get_registry());
+    $this->expectDeprecation('theme_get_registry() is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use theme.registry service method getRuntime() instead. See https://www.drupal.org/node/3348850');
+    $this->assertEquals($registry->getRuntime(), theme_get_registry(FALSE));
+  }
+
 }