diff --git a/app/code/Magento/Sales/Model/OrderRepository.php b/app/code/Magento/Sales/Model/OrderRepository.php
index 9a1392fbe9065..79548cb190754 100644
--- a/app/code/Magento/Sales/Model/OrderRepository.php
+++ b/app/code/Magento/Sales/Model/OrderRepository.php
@@ -6,7 +6,9 @@
 
 namespace Magento\Sales\Model;
 
+use Magento\Framework\Api\ExtensionAttribute\JoinProcessorInterface;
 use Magento\Framework\Api\SearchCriteria\CollectionProcessorInterface;
+use Magento\Framework\App\ObjectManager;
 use Magento\Framework\Exception\InputException;
 use Magento\Framework\Exception\NoSuchEntityException;
 use Magento\Sales\Api\Data\OrderExtensionFactory;
@@ -16,7 +18,6 @@
 use Magento\Sales\Api\Data\ShippingAssignmentInterface;
 use Magento\Sales\Model\Order\ShippingAssignmentBuilder;
 use Magento\Sales\Model\ResourceModel\Metadata;
-use Magento\Framework\App\ObjectManager;
 use Magento\Tax\Api\OrderTaxManagementInterface;
 use Magento\Payment\Api\Data\PaymentAdditionalInfoInterface;
 use Magento\Payment\Api\Data\PaymentAdditionalInfoInterfaceFactory;
@@ -74,6 +75,11 @@ class OrderRepository implements \Magento\Sales\Api\OrderRepositoryInterface
      */
     private $serializer;
 
+    /**
+     * @var JoinProcessorInterface
+     */
+    private $extensionAttributesJoinProcessor;
+
     /**
      * Constructor
      *
@@ -84,6 +90,7 @@ class OrderRepository implements \Magento\Sales\Api\OrderRepositoryInterface
      * @param OrderTaxManagementInterface|null $orderTaxManagement
      * @param PaymentAdditionalInfoInterfaceFactory|null $paymentAdditionalInfoFactory
      * @param JsonSerializer|null $serializer
+     * @param JoinProcessorInterface $extensionAttributesJoinProcessor
      */
     public function __construct(
         Metadata $metadata,
@@ -92,7 +99,8 @@ public function __construct(
         \Magento\Sales\Api\Data\OrderExtensionFactory $orderExtensionFactory = null,
         OrderTaxManagementInterface $orderTaxManagement = null,
         PaymentAdditionalInfoInterfaceFactory $paymentAdditionalInfoFactory = null,
-        JsonSerializer $serializer = null
+        JsonSerializer $serializer = null,
+        JoinProcessorInterface $extensionAttributesJoinProcessor = null
     ) {
         $this->metadata = $metadata;
         $this->searchResultFactory = $searchResultFactory;
@@ -106,6 +114,8 @@ public function __construct(
             ->get(PaymentAdditionalInfoInterfaceFactory::class);
         $this->serializer = $serializer ?: ObjectManager::getInstance()
             ->get(JsonSerializer::class);
+        $this->extensionAttributesJoinProcessor = $extensionAttributesJoinProcessor
+            ?: ObjectManager::getInstance()->get(JoinProcessorInterface::class);
     }
 
     /**
@@ -198,6 +208,7 @@ public function getList(\Magento\Framework\Api\SearchCriteriaInterface $searchCr
     {
         /** @var \Magento\Sales\Api\Data\OrderSearchResultInterface $searchResult */
         $searchResult = $this->searchResultFactory->create();
+        $this->extensionAttributesJoinProcessor->process($searchResult);
         $this->collectionProcessor->process($searchCriteria, $searchResult);
         $searchResult->setSearchCriteria($searchCriteria);
         foreach ($searchResult->getItems() as $order) {
diff --git a/dev/tests/api-functional/_files/Magento/TestModuleJoinDirectives/etc/extension_attributes.xml b/dev/tests/api-functional/_files/Magento/TestModuleJoinDirectives/etc/extension_attributes.xml
index 3bd64a7aff728..8254a9d8e92cf 100644
--- a/dev/tests/api-functional/_files/Magento/TestModuleJoinDirectives/etc/extension_attributes.xml
+++ b/dev/tests/api-functional/_files/Magento/TestModuleJoinDirectives/etc/extension_attributes.xml
@@ -31,4 +31,16 @@
             </join>
         </attribute>
     </extension_attributes>
+    <extension_attributes for="Magento\Sales\Api\Data\OrderInterface">
+        <attribute code="orderApiTestAttribute" type="Magento\User\Api\Data\UserInterface">
+            <join reference_table="admin_user"
+                  join_on_field="store_id"
+                  reference_field="user_id"
+            >
+                <field>firstname</field>
+                <field>lastname</field>
+                <field>email</field>
+            </join>
+        </attribute>
+    </extension_attributes>
 </config>
diff --git a/dev/tests/api-functional/testsuite/Magento/Webapi/JoinDirectivesTest.php b/dev/tests/api-functional/testsuite/Magento/Webapi/JoinDirectivesTest.php
index 5f967758e21bd..8beb14e81be71 100644
--- a/dev/tests/api-functional/testsuite/Magento/Webapi/JoinDirectivesTest.php
+++ b/dev/tests/api-functional/testsuite/Magento/Webapi/JoinDirectivesTest.php
@@ -6,12 +6,14 @@
 
 namespace Magento\Webapi;
 
+use Magento\Framework\Api\FilterBuilder;
 use Magento\Framework\Api\SearchCriteriaBuilder;
-use Magento\Framework\Api\SortOrderBuilder;
 use Magento\Framework\Api\SortOrder;
-use Magento\Framework\Api\SearchCriteria;
-use Magento\Framework\Api\FilterBuilder;
+use Magento\Framework\Api\SortOrderBuilder;
 
+/**
+ * Test join directives.
+ */
 class JoinDirectivesTest extends \Magento\TestFramework\TestCase\WebapiAbstract
 {
     /**
@@ -44,7 +46,8 @@ protected function setUp()
     }
 
     /**
-     * Rollback rules
+     * Rollback rules.
+     *
      * @magentoApiDataFixture Magento/SalesRule/_files/rules_rollback.php
      * @magentoApiDataFixture Magento/Sales/_files/quote.php
      */
@@ -124,6 +127,49 @@ public function testAutoGeneratedGetList()
         $this->assertEquals($expectedExtensionAttributes['email'], $testAttribute['email']);
     }
 
+    /**
+     * Test get list of orders with extension attributes.
+     *
+     * @magentoApiDataFixture Magento/Sales/_files/order.php
+     */
+    public function testGetOrdertList()
+    {
+        $filter = $this->filterBuilder
+            ->setField('increment_id')
+            ->setValue('100000001')
+            ->setConditionType('eq')
+            ->create();
+        $this->searchBuilder->addFilters([$filter]);
+        $searchData = $this->searchBuilder->create()->__toArray();
+
+        $requestData = ['searchCriteria' => $searchData];
+
+        $restResourcePath = '/V1/orders/';
+        $soapService = 'salesOrderRepositoryV1';
+        $expectedExtensionAttributes = $this->getExpectedExtensionAttributes();
+
+        $serviceInfo = [
+            'rest' => [
+                'resourcePath' => $restResourcePath . '?' . http_build_query($requestData),
+                'httpMethod' => \Magento\Framework\Webapi\Rest\Request::HTTP_METHOD_GET,
+            ],
+            'soap' => [
+                'service' => $soapService,
+                'operation' => $soapService . 'GetList',
+            ],
+        ];
+        $searchResult = $this->_webApiCall($serviceInfo, $requestData);
+
+        $this->assertArrayHasKey('items', $searchResult);
+        $itemData = array_pop($searchResult['items']);
+        $this->assertArrayHasKey('extension_attributes', $itemData);
+        $this->assertArrayHasKey('order_api_test_attribute', $itemData['extension_attributes']);
+        $testAttribute = $itemData['extension_attributes']['order_api_test_attribute'];
+        $this->assertEquals($expectedExtensionAttributes['firstname'], $testAttribute['first_name']);
+        $this->assertEquals($expectedExtensionAttributes['lastname'], $testAttribute['last_name']);
+        $this->assertEquals($expectedExtensionAttributes['email'], $testAttribute['email']);
+    }
+
     /**
      * Retrieve the admin user's information.
      *