diff --git a/core/modules/jsonapi/jsonapi.services.yml b/core/modules/jsonapi/jsonapi.services.yml
index 21599d4ce3..9d6c0ef0b9 100644
--- a/core/modules/jsonapi/jsonapi.services.yml
+++ b/core/modules/jsonapi/jsonapi.services.yml
@@ -188,6 +188,7 @@ services:
       - '@jsonapi.serializer'
       - '@datetime.time'
       - '@current_user'
+      - '@language_manager'
   jsonapi.file_upload:
     class: Drupal\jsonapi\Controller\FileUpload
     arguments:
diff --git a/core/modules/jsonapi/src/Controller/EntityResource.php b/core/modules/jsonapi/src/Controller/EntityResource.php
index 7f03511e47..3abcc594a7 100644
--- a/core/modules/jsonapi/src/Controller/EntityResource.php
+++ b/core/modules/jsonapi/src/Controller/EntityResource.php
@@ -22,6 +22,8 @@
 use Drupal\Core\Entity\RevisionLogInterface;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Language\LanguageInterface;
+use Drupal\Core\Language\LanguageManagerInterface;
 use Drupal\Core\Render\RenderContext;
 use Drupal\Core\Render\RendererInterface;
 use Drupal\Core\Session\AccountInterface;
@@ -151,6 +153,13 @@ class EntityResource {
    */
   protected $user;
 
+  /**
+   * The language manager.
+   *
+   * @var \Drupal\Core\Language\LanguageManagerInterface
+   */
+  protected $languageManager;
+
   /**
    * Instantiates an EntityResource object.
    *
@@ -176,8 +185,10 @@ class EntityResource {
    *   The time service.
    * @param \Drupal\Core\Session\AccountInterface $user
    *   The current user account.
+   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
+   *   The language manager.
    */
-  public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityFieldManagerInterface $field_manager, ResourceTypeRepositoryInterface $resource_type_repository, RendererInterface $renderer, EntityRepositoryInterface $entity_repository, IncludeResolver $include_resolver, EntityAccessChecker $entity_access_checker, FieldResolver $field_resolver, SerializerInterface $serializer, TimeInterface $time, AccountInterface $user) {
+  public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityFieldManagerInterface $field_manager, ResourceTypeRepositoryInterface $resource_type_repository, RendererInterface $renderer, EntityRepositoryInterface $entity_repository, IncludeResolver $include_resolver, EntityAccessChecker $entity_access_checker, FieldResolver $field_resolver, SerializerInterface $serializer, TimeInterface $time, AccountInterface $user, LanguageManagerInterface $language_manager) {
     $this->entityTypeManager = $entity_type_manager;
     $this->fieldManager = $field_manager;
     $this->resourceTypeRepository = $resource_type_repository;
@@ -189,6 +200,7 @@ public function __construct(EntityTypeManagerInterface $entity_type_manager, Ent
     $this->serializer = $serializer;
     $this->time = $time;
     $this->user = $user;
+    $this->languageManager = $language_manager;
   }
 
   /**
@@ -884,7 +896,7 @@ protected function getCollectionQuery(ResourceType $resource_type, array $params
       foreach ($sort->fields() as $field) {
         $path = $this->fieldResolver->resolveInternalEntityQueryPath($resource_type, $field[Sort::PATH_KEY]);
         $direction = isset($field[Sort::DIRECTION_KEY]) ? $field[Sort::DIRECTION_KEY] : 'ASC';
-        $langcode = isset($field[Sort::LANGUAGE_KEY]) ? $field[Sort::LANGUAGE_KEY] : NULL;
+        $langcode = isset($field[Sort::LANGUAGE_KEY]) ? $field[Sort::LANGUAGE_KEY] : $this->languageManager->getCurrentLanguage(LanguageInterface::TYPE_CONTENT)->getId();
         $query->sort($path, $direction, $langcode);
       }
     }
diff --git a/core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalMultilingualTest.php b/core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalMultilingualTest.php
index abe0a73d69..80d07f4dc8 100644
--- a/core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalMultilingualTest.php
+++ b/core/modules/jsonapi/tests/src/Functional/JsonApiFunctionalMultilingualTest.php
@@ -57,14 +57,13 @@ protected function setUp(): void {
     ])
       ->setThirdPartySetting('content_translation', 'enabled', TRUE)
       ->save();
-
-    $this->createDefaultContent(5, 5, TRUE, TRUE, static::IS_MULTILINGUAL, FALSE);
   }
 
   /**
    * Tests reading multilingual content.
    */
   public function testReadMultilingual() {
+    $this->createDefaultContent(5, 5, TRUE, TRUE, static::IS_MULTILINGUAL, FALSE);
     // Different databases have different sort orders, so a sort is required so
     // test expectations do not need to vary per database.
     $default_sort = ['sort' => 'drupal_internal__nid'];
@@ -98,6 +97,7 @@ public function testReadMultilingual() {
    * Tests updating a translation.
    */
   public function testPatchTranslation() {
+    $this->createDefaultContent(5, 5, TRUE, TRUE, static::IS_MULTILINGUAL, FALSE);
     $this->config('jsonapi.settings')->set('read_only', FALSE)->save(TRUE);
     $node = $this->nodes[0];
     $uuid = $node->uuid();
@@ -197,6 +197,7 @@ public function testPatchTranslation() {
    * Tests updating a translation fallback.
    */
   public function testPatchTranslationFallback() {
+    $this->createDefaultContent(5, 5, TRUE, TRUE, static::IS_MULTILINGUAL, FALSE);
     $this->config('jsonapi.settings')->set('read_only', FALSE)->save(TRUE);
     $node = $this->nodes[0];
     $uuid = $node->uuid();
@@ -238,6 +239,7 @@ public function testPatchTranslationFallback() {
    * Tests creating a translation.
    */
   public function testPostTranslation() {
+    $this->createDefaultContent(5, 5, TRUE, TRUE, static::IS_MULTILINGUAL, FALSE);
     $this->config('jsonapi.settings')->set('read_only', FALSE)->save(TRUE);
     $this->grantPermissions(Role::load(RoleInterface::ANONYMOUS_ID), [
       'bypass node access',
@@ -302,6 +304,7 @@ public function testPostTranslation() {
    * Tests deleting multilingual content.
    */
   public function testDeleteMultilingual() {
+    $this->createDefaultContent(5, 5, TRUE, TRUE, static::IS_MULTILINGUAL, FALSE);
     $this->config('jsonapi.settings')->set('read_only', FALSE)->save(TRUE);
     $this->grantPermissions(Role::load(RoleInterface::ANONYMOUS_ID), [
       'bypass node access',
@@ -322,4 +325,59 @@ public function testDeleteMultilingual() {
     $this->assertNull(Node::load($this->nodes[0]->id()));
   }
 
+  /**
+   * Tests multilingual JSON:API calls.
+   */
+  public function testMultilingualGet() {
+    $titles = [
+      [
+        'en' => 'Apple',
+        'ca' => 'Z-Apple',
+      ],
+      [
+        'en' => 'Blackberry',
+        'ca' => 'Y-Blackberry',
+      ],
+      [
+        'en' => 'Google',
+        'ca' => 'X-Google',
+      ],
+      [
+        'en' => 'Motorola',
+        'ca' => 'W-Motorola',
+      ],
+    ];
+
+    $expected_english_order = ['Apple', 'Blackberry', 'Google', 'Motorola'];
+    $expected_ca_order = ['W-Motorola', 'X-Google', 'Y-Blackberry', 'Z-Apple'];
+    foreach ($titles as $title) {
+      $node = Node::create(['title' => $title['en'], 'type' => 'article', 'langcode' => 'en']);
+      $node->addTranslation('ca', ['title' => $title['ca']]);
+      $node->save();
+    }
+
+    $output = Json::decode($this->drupalGet('/jsonapi/node/article', [
+      'query' => [
+        'sort' => 'title',
+      ],
+    ]));
+    $output_titles = array_map(function ($result) {
+      return $result['attributes']['title'];
+    }, $output['data']);
+    $this->assertCount(4, $output_titles);
+    $this->assertSame($expected_english_order, $output_titles);
+
+    // Check the nodes with the langcode url.
+    $output = Json::decode($this->drupalGet('/ca/jsonapi/node/article', [
+      'query' => [
+        'sort' => 'title',
+      ],
+    ]));
+    $output_titles = array_map(function ($result) {
+      return $result['attributes']['title'];
+    }, $output['data']);
+    $this->assertCount(4, $output_titles);
+    $this->assertSame($expected_ca_order, $output_titles);
+  }
+
 }