diff --git a/src/Admin/AbstractAdmin.php b/src/Admin/AbstractAdmin.php
index 86800981944..abd214c3996 100644
--- a/src/Admin/AbstractAdmin.php
+++ b/src/Admin/AbstractAdmin.php
@@ -391,6 +391,8 @@ abstract class AbstractAdmin implements AdminInterface, DomainObjectInterface, A
     protected $securityHandler;
 
     /**
+     * NEXT_MAJOR: Remove this property.
+     *
      * @var ValidatorInterface
      */
     protected $validator;
@@ -2848,6 +2850,11 @@ public function id($model)
         return $this->getNormalizedIdentifier($model);
     }
 
+    /**
+     * NEXT_MAJOR: Remove this method.
+     *
+     * @deprecated since sonata-project/admin-bundle 3.x.
+     */
     public function setValidator($validator)
     {
         // NEXT_MAJOR: Move ValidatorInterface check to method signature
@@ -2861,8 +2868,18 @@ public function setValidator($validator)
         $this->validator = $validator;
     }
 
+    /**
+     * NEXT_MAJOR: Remove this method.
+     *
+     * @deprecated since sonata-project/admin-bundle 3.x.
+     */
     public function getValidator()
     {
+        @trigger_error(sprintf(
+            'The %s method is deprecated since version 3.x and will be removed in 4.0.',
+            __METHOD__
+        ), E_USER_DEPRECATED);
+
         return $this->validator;
     }
 
diff --git a/src/Admin/AdminInterface.php b/src/Admin/AdminInterface.php
index 6555e1398eb..34e6bc68290 100644
--- a/src/Admin/AdminInterface.php
+++ b/src/Admin/AdminInterface.php
@@ -328,14 +328,22 @@ public function getNormalizedIdentifier($model);
     public function id($model);
 
     /**
+     * NEXT_MAJOR: remove this method.
+     *
      * @param ValidatorInterface $validator
      *
      * @return void
+     *
+     * @deprecated since sonata-project/admin-bundle 3.x.
      */
     public function setValidator($validator);
 
     /**
+     * NEXT_MAJOR: remove this method.
+     *
      * @return ValidatorInterface
+     *
+     * @deprecated since sonata-project/admin-bundle 3.x.
      */
     public function getValidator();
 
diff --git a/src/DependencyInjection/Compiler/AddDependencyCallsCompilerPass.php b/src/DependencyInjection/Compiler/AddDependencyCallsCompilerPass.php
index 854767da767..b6d3d87bc34 100644
--- a/src/DependencyInjection/Compiler/AddDependencyCallsCompilerPass.php
+++ b/src/DependencyInjection/Compiler/AddDependencyCallsCompilerPass.php
@@ -232,7 +232,7 @@ public function applyConfigurationFromAttribute(Definition $definition, array $a
             'translator',
             'configuration_pool',
             'router',
-            'validator',
+            'validator', //NEXT_MAJOR: Remove this line
             'security_handler',
             'menu_factory',
             'route_builder',
@@ -280,7 +280,7 @@ public function applyDefaults(ContainerBuilder $container, $serviceId, array $at
             'translator' => 'translator',
             'configuration_pool' => 'sonata.admin.pool',
             'route_generator' => 'sonata.admin.route.default_generator',
-            'validator' => 'validator',
+            'validator' => 'validator', //NEXT_MAJOR: Remove this line
             'security_handler' => 'sonata.admin.security.handler',
             'menu_factory' => 'knp_menu.factory',
             'route_builder' => 'sonata.admin.route.path_info'.
diff --git a/src/DependencyInjection/Configuration.php b/src/DependencyInjection/Configuration.php
index 695fc96dcf5..881e00c642f 100644
--- a/src/DependencyInjection/Configuration.php
+++ b/src/DependencyInjection/Configuration.php
@@ -353,6 +353,7 @@ public function getConfigTreeBuilder()
                             ->scalarNode('translator')->defaultNull()->end()
                             ->scalarNode('configuration_pool')->defaultNull()->end()
                             ->scalarNode('route_generator')->defaultNull()->end()
+                            // NEXT_MAJOR: remove validator option
                             ->scalarNode('validator')->defaultNull()->end()
                             ->scalarNode('security_handler')->defaultNull()->end()
                             ->scalarNode('label')->defaultNull()->end()
diff --git a/tests/Admin/AdminTest.php b/tests/Admin/AdminTest.php
index c34c5c59031..b9b1a75298c 100644
--- a/tests/Admin/AdminTest.php
+++ b/tests/Admin/AdminTest.php
@@ -954,6 +954,11 @@ public function testGetFormTheme(): void
         $this->assertSame(['FooTheme'], $admin->getFormTheme());
     }
 
+    /*
+     * @group legacy
+     *
+     * NEXT_MAJOR: remove this test
+     */
     public function testGetValidator(): void
     {
         $admin = new PostAdmin('sonata.post.admin.post', 'NewsBundle\Entity\Post', 'Sonata\NewsBundle\Controller\PostAdminController');
@@ -964,6 +969,7 @@ public function testGetValidator(): void
 
         $admin->setValidator($validator);
         $this->assertSame($validator, $admin->getValidator());
+        $this->expectDeprecation('Since sonata-project/admin-bundle 3.x: This "%s" method is deprecated');
     }
 
     public function testGetSecurityHandler(): void