diff --git a/apps/st/src/components/module/SearchForm.tsx b/apps/st/src/components/module/SearchForm.tsx
index 08b6e2b50..ccc76bc3d 100644
--- a/apps/st/src/components/module/SearchForm.tsx
+++ b/apps/st/src/components/module/SearchForm.tsx
@@ -172,6 +172,30 @@ const SearchForm = (props: SearchFormProps = {}) => {
     );
     const sggOptions = sggList?.data ?? [];
 
+    // 시도 설정 후 시군구 목록이 오면 첫 번째 항목 자동 선택
+    useEffect(() => {
+        if (!mergedProps.gugun) return;
+        if (props.defaultValues?.gugun) return;
+        if (!values.sido || values.sido === "ALL") return;
+
+        const firstSgg = sggList?.data?.[0];
+        if (!firstSgg) return;
+
+        setValues((prev) => {
+            if (prev.gugun) return prev;
+            return {
+                ...prev,
+                gugun: firstSgg.gugun,
+                bsnmCd: firstSgg.bsnmCd,
+            };
+        });
+    }, [
+        sggList,
+        values.sido,
+        mergedProps.gugun,
+        props.defaultValues?.gugun,
+    ]);
+
     const handleSubmit = (e: React.FormEvent<HTMLFormElement>) => {
         e.preventDefault();
         props.onSubmit?.(values);