diff -u b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
--- b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
+++ b/core/modules/config/lib/Drupal/config/Controller/ConfigController.php
@@ -102,15 +102,23 @@
   /**
    * Shows diff of specificed configuration file.
    *
-   * @param string $config_file
+   * @param string $source_name
    *   The name of the configuration file.
+   * @param string $target_name
+   *   (optional) The name of the target configuration file if different from
+   *   the $source_name.
+   * @param string $collection
+   *   (optional) The configuration collection name. Defaults to the default
+   *   collection.
    *
    * @return string
    *   Table showing a two-way diff between the active and staged configuration.
    */
-  public function diff($source_name, $target_name = NULL) {
-
-    $diff = $this->configManager->diff($this->targetStorage, $this->sourceStorage, $source_name, $target_name);
+  public function diff($source_name, $target_name = NULL, $collection = NULL) {
+    if (!isset($collection)) {
+      $collection = StorageInterface::DEFAULT_COLLECTION;
+    }
+    $diff = $this->configManager->diff($this->targetStorage, $this->sourceStorage, $source_name, $target_name, $collection);
     $formatter = new \DrupalDiffFormatter();
     $formatter->show_header = FALSE;
 
diff -u b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
--- b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
+++ b/core/modules/config/lib/Drupal/config/Form/ConfigSync.php
@@ -226,14 +226,20 @@
         );
 
         foreach ($config_names as $config_name) {
-          // @todo Add collection to diffing
           if ($config_change_type == 'rename') {
             $names = $storage_comparer->extractRenameNames($config_name);
-            $href = $this->urlGenerator->getPathFromRoute('config.diff', array('source_name' => $names['old_name'], 'target_name' => $names['new_name']));
+            $route_options = array('source_name' => $names['old_name'], 'target_name' => $names['new_name']);
             $config_name = $this->t('!source_name to !target_name', array('!source_name' => $names['old_name'], '!target_name' => $names['new_name']));
           }
           else {
-            $href = $this->urlGenerator->getPathFromRoute('config.diff', array('source_name' => $config_name));
+            $route_options = array('source_name' => $config_name);
+          }
+          if ($collection != StorageInterface::DEFAULT_COLLECTION) {
+            $route_options['collection'] = $collection;
+            $href = $this->urlGenerator->getPathFromRoute('config.diff_collection', $route_options);
+          }
+          else {
+            $href = $this->urlGenerator->getPathFromRoute('config.diff', $route_options);
           }
           $links['view_diff'] = array(
             'title' => $this->t('View differences'),
diff -u b/core/modules/config/lib/Drupal/config/Tests/ConfigExportImportUITest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigExportImportUITest.php
--- b/core/modules/config/lib/Drupal/config/Tests/ConfigExportImportUITest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigExportImportUITest.php
@@ -176,6 +176,24 @@
     $this->assertFalse(in_array('collection/test2/config_test.another_delete.yml', $files), 'Config export does not contain collection/test2/config_test.another_delete.yml.');
 
     $this->drupalPostForm('admin/config/development/configuration/full/import', array('files[import_tarball]' => $filename), 'Upload');
+    // Verify that there are configuration differences to import.
+    $this->drupalGet('admin/config/development/configuration');
+    $this->assertNoText(t('There are no configuration changes.'));
+    $this->assertText(t('!collection configuration collection', array('!collection' => 'collection.test1')));
+    $this->assertText(t('!collection configuration collection', array('!collection' => 'collection.test2')));
+    $this->assertText('config_test.create');
+    $this->assertLinkByHref('admin/config/development/configuration/sync/diff_collection/collection.test1/config_test.create');
+    $this->assertText('config_test.update');
+    $this->assertLinkByHref('admin/config/development/configuration/sync/diff_collection/collection.test1/config_test.update');
+    $this->assertText('config_test.delete');
+    $this->assertLinkByHref('admin/config/development/configuration/sync/diff_collection/collection.test1/config_test.delete');
+    $this->assertText('config_test.another_create');
+    $this->assertLinkByHref('admin/config/development/configuration/sync/diff_collection/collection.test2/config_test.another_create');
+    $this->assertText('config_test.another_update');
+    $this->assertLinkByHref('admin/config/development/configuration/sync/diff_collection/collection.test2/config_test.another_update');
+    $this->assertText('config_test.another_delete');
+    $this->assertLinkByHref('admin/config/development/configuration/sync/diff_collection/collection.test2/config_test.another_delete');
+
     $this->drupalPostForm(NULL, array(), 'Import all');
     $this->assertText(t('There are no configuration changes.'));
 
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Config/ConfigManager.php
+++ b/core/lib/Drupal/Core/Config/ConfigManager.php
@@ -100,7 +100,11 @@ public function getConfigFactory() {
   /**
    * {@inheritdoc}
    */
-  public function diff(StorageInterface $source_storage, StorageInterface $target_storage, $source_name, $target_name = NULL) {
+  public function diff(StorageInterface $source_storage, StorageInterface $target_storage, $source_name, $target_name = NULL, $collection = StorageInterface::DEFAULT_COLLECTION) {
+    if ($collection != StorageInterface::DEFAULT_COLLECTION) {
+      $source_storage = $source_storage->createCollection($collection);
+      $target_storage = $target_storage->createCollection($collection);
+    }
     if (!isset($target_name)) {
       $target_name = $source_name;
     }
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Config/ConfigManagerInterface.php
+++ b/core/lib/Drupal/Core/Config/ConfigManagerInterface.php
@@ -51,13 +51,16 @@ public function getConfigFactory();
    * @param string $target_name
    *   (optional) The name of the configuration object in the target storage.
    *   If omitted, the source name is used.
+   * @param string $collection
+   *   (optional) The configuration collection name. Defaults to the default
+   *   collection.
    *
    * @return core/lib/Drupal/Component/Diff
    *   A formatted string showing the difference between the two storages.
    *
    * @todo Make renderer injectable
    */
-  public function diff(StorageInterface $source_storage, StorageInterface $target_storage, $source_name, $target_name = NULL);
+  public function diff(StorageInterface $source_storage, StorageInterface $target_storage, $source_name, $target_name = NULL, $collection = StorageInterface::DEFAULT_COLLECTION);
 
   /**
    * Creates a configuration snapshot following a successful import.
only in patch2:
unchanged:
--- a/core/modules/config/config.routing.yml
+++ b/core/modules/config/config.routing.yml
@@ -14,6 +14,14 @@ config.diff:
   requirements:
     _permission: 'synchronize configuration'
 
+config.diff_collection:
+  path: '/admin/config/development/configuration/sync/diff_collection/{collection}/{source_name}/{target_name}'
+  defaults:
+    _content: '\Drupal\config\Controller\ConfigController::diff'
+    target_name: NULL
+  requirements:
+    _permission: 'synchronize configuration'
+
 config.export_download:
   path: '/admin/config/development/configuration/full/export-download'
   defaults:
only in patch2:
unchanged:
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigDiffTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigDiffTest.php
@@ -113,4 +113,36 @@ function testDiff() {
     $this->assertEqual(count($diff->edits), 2, 'There are two items in the diff.');
   }
 
+  /**
+   * Tests calculating the difference between two sets of config collections.
+   */
+  function testCollectionDiff() {
+    /** @var \Drupal\Core\Config\StorageInterface $active */
+    $active = $this->container->get('config.storage');
+    /** @var \Drupal\Core\Config\StorageInterface $staging */
+    $staging = $this->container->get('config.storage.staging');
+    $active_test_collection = $active->createCollection('test');
+    $staging_test_collection = $staging->createCollection('test');
+
+    $config_name = 'config_test.test';
+    $data = array('foo' => 'bar');
+
+    $active->write($config_name, $data);
+    $staging->write($config_name, $data);
+    $active_test_collection->write($config_name, $data);
+    $staging_test_collection->write($config_name, array('foo' => 'baz'));
+
+    // Test the fields match in the default collection diff.
+    $diff = \Drupal::service('config.manager')->diff($active, $staging, $config_name);
+    $this->assertEqual($diff->edits[0]->type, 'copy',  'The first item in the diff is a copy.');
+    $this->assertEqual(count($diff->edits), 1, 'There is one item in the diff');
+
+    // Test that the differences are detected when diffing the collection.
+    $diff = \Drupal::service('config.manager')->diff($active, $staging, $config_name, NULL, 'test');
+    $this->assertEqual($diff->edits[0]->type, 'change',  'The second item in the diff is a copy.');
+    $this->assertEqual($diff->edits[0]->orig, array('foo: bar'));
+    $this->assertEqual($diff->edits[0]->closing, array('foo: baz'));
+    $this->assertEqual($diff->edits[1]->type, 'copy',  'The second item in the diff is a copy.');
+  }
+
 }