diff --git a/frontend/components/admin/dashboard/WidgetConfigSidebar.tsx b/frontend/components/admin/dashboard/WidgetConfigSidebar.tsx
index e79c6446..9fcfe296 100644
--- a/frontend/components/admin/dashboard/WidgetConfigSidebar.tsx
+++ b/frontend/components/admin/dashboard/WidgetConfigSidebar.tsx
@@ -566,7 +566,21 @@ export function WidgetConfigSidebar({ element, isOpen, onClose, onApply }: Widge
         <Button variant="outline" onClick={onClose} className="h-9 flex-1 text-sm">
           취소
         </Button>
-        <Button onClick={handleApply} className="h-9 flex-1 text-sm">
+        <Button 
+          onClick={handleApply} 
+          className="h-9 flex-1 text-sm"
+          disabled={
+            // 다중 데이터 소스 위젯: dataSources가 비어있거나 endpoint가 없으면 비활성화
+            (element?.subtype === "map-summary-v2" || 
+             element?.subtype === "chart" || 
+             element?.subtype === "list-v2" || 
+             element?.subtype === "custom-metric-v2" || 
+             element?.subtype === "risk-alert-v2") &&
+            (!dataSources || 
+             dataSources.length === 0 || 
+             dataSources.some(ds => ds.type === "api" && !ds.endpoint))
+          }
+        >
           적용
         </Button>
       </div>