diff --git "a/5\354\243\274\354\260\250 Server S-Day \352\263\274\354\240\234/files_leeseohyun/S3Controller.java" "b/5\354\243\274\354\260\250 Server S-Day \352\263\274\354\240\234/files_leeseohyun/S3Controller.java"
new file mode 100644
index 0000000..c08ae6e
--- /dev/null
+++ "b/5\354\243\274\354\260\250 Server S-Day \352\263\274\354\240\234/files_leeseohyun/S3Controller.java"	
@@ -0,0 +1,53 @@
+package ServerStudy5Cloud.ServerStudy5Cloud.Controller;
+
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.model.CannedAccessControlList;
+import com.amazonaws.services.s3.model.S3ObjectSummary;
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.multipart.MultipartFile;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+
+@Controller
+@RequiredArgsConstructor
+public class S3Controller {
+
+    private final AmazonS3 amazonS3;
+
+    @Value("${cloud.aws.s3.bucket}")
+    private String bucketName;
+
+    @GetMapping("/")
+    public String listFiles(Model model) {
+        // S3 버킷의 객체 목록 가져오기
+        List<S3ObjectSummary> objectSummaries = amazonS3.listObjectsV2(bucketName).getObjectSummaries();
+        // getUrl로 객체 URL 가져온 후, List<String>에 넣어 index.html에 반환
+        List<String> fileUrls = new ArrayList<>();
+        for (S3ObjectSummary os : objectSummaries) {
+            String url = amazonS3.getUrl(bucketName, os.getKey()).toString();
+            fileUrls.add(url);
+        }
+        model.addAttribute("fileUrls", fileUrls);
+        return "index";
+    }
+
+    @PostMapping("/upload")
+    public String uploadFile(@RequestParam("file") MultipartFile file) throws IOException {
+        String filename = file.getOriginalFilename();
+        // putObject로 파일을 S3 버킷에 업로드
+        amazonS3.putObject(bucketName, filename, file.getInputStream(), null);
+        // ACL 퍼블릭으로 설정
+        amazonS3.setObjectAcl(bucketName, filename, CannedAccessControlList.PublicRead);
+        return "redirect:/";
+    }
+}
+// 동작 영상 : https://drive.google.com/file/d/10wPjsBbnbIR5E6pKbwmr2sZ-GsLY-FWP/view?usp=sharing
\ No newline at end of file
diff --git "a/5\354\243\274\354\260\250 Server S-Day \352\263\274\354\240\234/files_leeseohyun/application.yml" "b/5\354\243\274\354\260\250 Server S-Day \352\263\274\354\240\234/files_leeseohyun/application.yml"
new file mode 100644
index 0000000..4b7489c
--- /dev/null
+++ "b/5\354\243\274\354\260\250 Server S-Day \352\263\274\354\240\234/files_leeseohyun/application.yml"	
@@ -0,0 +1,15 @@
+spring:
+  config:
+    import: optional:file:.env[.properties]
+# 이렇게 .env 파일을 사용하려고 했지만 잘 동작하지 않아서... 빌드 Edit Configuration에서 Environment variables로 설정해서 했습니다...!
+cloud:
+  aws:
+    s3:
+      bucket: ${S3_BUCKET}
+    stack.auto: false
+    region.static: ap-northeast-2
+    credentials:
+      access-key: ${CREDENTIALS_ACCESS_KEY}
+      secret-key: ${CREDENTIALS_SECRET_KEY}
+server:
+  port: 8080
\ No newline at end of file
diff --git "a/5\354\243\274\354\260\250 Server S-Day \352\263\274\354\240\234/\354\235\264\354\204\234\355\230\204_5\354\243\274\354\260\250_\352\263\274\354\240\234.md" "b/5\354\243\274\354\260\250 Server S-Day \352\263\274\354\240\234/\354\235\264\354\204\234\355\230\204_5\354\243\274\354\260\250_\352\263\274\354\240\234.md"
new file mode 100644
index 0000000..e69de29