diff --git a/application/common/components/ExternalGroupsSync.php b/application/common/components/ExternalGroupsSync.php
new file mode 100644
index 00000000..2fc33bc7
--- /dev/null
+++ b/application/common/components/ExternalGroupsSync.php
@@ -0,0 +1,66 @@
+<?php
+
+namespace common\components;
+
+use common\models\User;
+use Yii;
+use yii\base\Component;
+
+class ExternalGroupsSync extends Component
+{
+    public const MAX_SYNC_SETS = 20;
+
+    public static function syncAllSets(array $syncSetsParams)
+    {
+        for ($i = 1; $i <= self::MAX_SYNC_SETS; $i++) {
+            $appPrefixKey = sprintf('set%uAppPrefix', $i);
+            $googleSheetIdKey = sprintf('set%uGoogleSheetId', $i);
+
+            if (! array_key_exists($appPrefixKey, $syncSetsParams)) {
+                Yii::warning(sprintf(
+                    'Finished syncing external groups after %s sync set(s).',
+                    ($i - 1)
+                ));
+                break;
+            }
+
+            $appPrefix = $syncSetsParams[$appPrefixKey] ?? null;
+            $googleSheetId = $syncSetsParams[$googleSheetIdKey] ?? null;
+
+            if (empty($appPrefix) || empty($googleSheetId)) {
+                Yii::error(sprintf(
+                    'Unable to do external-groups sync set %s: '
+                    . 'app-prefix (%s) or Google Sheet ID (%s) was empty.',
+                    $i,
+                    json_encode($appPrefix),
+                    json_encode($googleSheetId),
+                ));
+            } else {
+                Yii::warning(sprintf(
+                    'Syncing %s external groups from Google Sheet (%s)...',
+                    json_encode($appPrefix),
+                    $googleSheetId
+                ));
+                self::syncSet($appPrefix, $googleSheetId);
+            }
+        }
+    }
+
+    private static function syncSet(string $appPrefix, string $googleSheetId)
+    {
+        $desiredExternalGroups = self::getExternalGroupsFromGoogleSheet($googleSheetId);
+        $errors = User::syncExternalGroups($appPrefix, $desiredExternalGroups);
+        Yii::warning(sprintf(
+            'Ran sync for %s external groups.',
+            $appPrefix
+        ));
+
+        if (! empty($errors)) {
+            Yii::error(sprintf(
+                "Errors that occurred while syncing %s external groups: \n%s",
+                $appPrefix,
+                join("\n", $errors)
+            ));
+        }
+    }
+}
diff --git a/application/common/config/main.php b/application/common/config/main.php
index 08f3bec7..b243e29d 100644
--- a/application/common/config/main.php
+++ b/application/common/config/main.php
@@ -239,6 +239,7 @@
             ],
             Env::getArrayFromPrefix('ABANDONED_USER_')
         ),
+        'externalGroupsSyncSets' => Env::getArrayFromPrefix('EXTERNAL_GROUPS_SYNC_'),
         'googleAnalytics'               => [
             'apiSecret' => Env::get('GA_API_SECRET'),
             'measurementId' => Env::get('GA_MEASUREMENT_ID'),
diff --git a/application/console/controllers/CronController.php b/application/console/controllers/CronController.php
index 22f15390..01c4648c 100644
--- a/application/console/controllers/CronController.php
+++ b/application/console/controllers/CronController.php
@@ -2,6 +2,7 @@
 
 namespace console\controllers;
 
+use common\components\ExternalGroupsSync;
 use common\helpers\Utils;
 use common\models\Invite;
 use common\models\Method;
@@ -137,6 +138,16 @@ public function actionExportToSheets()
         User::exportToSheets();
     }
 
+    /**
+     * Sync external groups from Google Sheets
+     */
+    public function actionSyncExternalGroups()
+    {
+        ExternalGroupsSync::syncAllSets(
+            \Yii::$app->params['externalGroupsSyncSets'] ?? []
+        );
+    }
+
     /**
      * Run all cron tasks, catching and logging errors to allow remaining tasks to run after an exception
      */
diff --git a/local.env.dist b/local.env.dist
index 6d2604aa..c460df7a 100644
--- a/local.env.dist
+++ b/local.env.dist
@@ -337,3 +337,11 @@ GOOGLE_delegatedAdmin=admin@example.com
 
 # spreadsheet ID
 GOOGLE_spreadsheetId=putAnActualSheetIDHerejD70xAjqPnOCHlDK3YomH
+
+# === external groups sync sets === #
+
+# EXTERNAL_GROUPS_SYNC_set1AppPrefix=
+# EXTERNAL_GROUPS_SYNC_set1GoogleSheetId=
+# EXTERNAL_GROUPS_SYNC_set2AppPrefix=
+# EXTERNAL_GROUPS_SYNC_set2GoogleSheetId=
+# ... with as many sets as you want.