diff --git a/to-lower-case/hyedall.py b/to-lower-case/hyedall.py
new file mode 100644
index 0000000000..a0bd222a56
--- /dev/null
+++ b/to-lower-case/hyedall.py
@@ -0,0 +1,10 @@
+"""
+https://leetcode.com/problems/to-lower-case/
+
+시간 복잡도: O(n)
+공간 복잡도: O(n)
+"""
+
+class Solution:
+    def toLowerCase(self, s: str) -> str:
+        return s.lower()