diff --git a/modules/openapi-generator/src/main/resources/dart2/api_client.mustache b/modules/openapi-generator/src/main/resources/dart2/api_client.mustache
index d307654943b3..a933252c0de6 100644
--- a/modules/openapi-generator/src/main/resources/dart2/api_client.mustache
+++ b/modules/openapi-generator/src/main/resources/dart2/api_client.mustache
@@ -31,7 +31,7 @@ class ApiClient {
   {{/isBasicBearer}}
   {{/isBasic}}
   {{#isApiKey}}
-    _authentications['{{name}}'] = ApiKeyAuth({{#isKeyInHeader}}"header"{{/isKeyInHeader}}{{^isKeyInHeader}}"query"{{/isKeyInHeader}}, "{{keyParamName}}");
+    _authentications['{{name}}'] = ApiKeyAuth({{#isKeyInCookie}}"cookie"{{/isKeyInCookie}}{{^isKeyInCookie}}{{#isKeyInHeader}}"header"{{/isKeyInHeader}}{{^isKeyInHeader}}"query"{{/isKeyInHeader}}{{/isKeyInCookie}}, "{{keyParamName}}");
   {{/isApiKey}}
   {{#isOAuth}}
     _authentications['{{name}}'] = OAuth();
diff --git a/modules/openapi-generator/src/main/resources/dart2/auth/api_key_auth.mustache b/modules/openapi-generator/src/main/resources/dart2/auth/api_key_auth.mustache
index c5e53204dc01..e429cd61dda2 100644
--- a/modules/openapi-generator/src/main/resources/dart2/auth/api_key_auth.mustache
+++ b/modules/openapi-generator/src/main/resources/dart2/auth/api_key_auth.mustache
@@ -24,6 +24,10 @@ class ApiKeyAuth implements Authentication {
       queryParams.add(QueryParam(paramName, value));
     } else if (location == 'header' && value != null) {
       headerParams[paramName] = value;
+    } else if (location == 'cookie' && value != null) {
+      headerParams.update('Cookie', (String existingCookie) {
+        return "$existingCookie; $paramName=$value";
+      }, ifAbsent: () => '$paramName=$value');
     }
   }
 }
diff --git a/samples/client/petstore/dart2/petstore_client_lib/lib/auth/api_key_auth.dart b/samples/client/petstore/dart2/petstore_client_lib/lib/auth/api_key_auth.dart
index 8384f0516ce2..78ffb2e0a216 100644
--- a/samples/client/petstore/dart2/petstore_client_lib/lib/auth/api_key_auth.dart
+++ b/samples/client/petstore/dart2/petstore_client_lib/lib/auth/api_key_auth.dart
@@ -24,6 +24,10 @@ class ApiKeyAuth implements Authentication {
       queryParams.add(QueryParam(paramName, value));
     } else if (location == 'header' && value != null) {
       headerParams[paramName] = value;
+    } else if (location == 'cookie' && value != null) {
+      headerParams.update('Cookie', (String existingCookie) {
+        return "$existingCookie; $paramName=$value";
+      }, ifAbsent: () => '$paramName=$value');
     }
   }
 }