diff --git a/src/main/java/com/example/FixLog/config/SecurityConfig.java b/src/main/java/com/example/FixLog/config/SecurityConfig.java
index ede3958..173c2fd 100644
--- a/src/main/java/com/example/FixLog/config/SecurityConfig.java
+++ b/src/main/java/com/example/FixLog/config/SecurityConfig.java
@@ -37,6 +37,8 @@ public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
                         .requestMatchers(HttpMethod.GET, "/members/check-nickname").permitAll()
                         .requestMatchers(HttpMethod.GET, "/", "/main", "/main/**").permitAll()
                         .requestMatchers(HttpMethod.GET, "/posts/**").permitAll()
+
+                        .requestMatchers("/api/s3/**").permitAll()
                         // h2-console (로컬 테스트용)
                         .requestMatchers(HttpMethod.GET, "/h2-console/**").permitAll()
                         // 배포 확인용 임시 허용
diff --git a/src/main/java/com/example/FixLog/controller/MypageMemberController.java b/src/main/java/com/example/FixLog/controller/MypageMemberController.java
index 05d115e..e5ace04 100644
--- a/src/main/java/com/example/FixLog/controller/MypageMemberController.java
+++ b/src/main/java/com/example/FixLog/controller/MypageMemberController.java
@@ -16,6 +16,8 @@
 import jakarta.validation.Valid;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.web.bind.annotation.*;
+import com.example.FixLog.dto.s3.PresignedUploadResponseDto;
+
 
 import java.util.Map;
 
@@ -55,9 +57,9 @@ public ResponseEntity<Response<PresignResponseDto>> presignProfileImage(
     ) {
         if (member == null) throw new CustomException(ErrorCode.UNAUTHORIZED);
 
-        String key = s3Service.generateKey("profile", filename);
-        String uploadUrl = s3Service.generatePresignedUrl("profile", filename, 15);
-        String fileUrl = s3Service.getObjectUrl(key);
+        PresignedUploadResponseDto responseDto = s3Service.generatePresignedUploadUrl("profile", filename, 15);
+        String uploadUrl = responseDto.getPresignedUrl();
+        String fileUrl = responseDto.getFileUrl();
 
         PresignResponseDto dto = new PresignResponseDto(uploadUrl, fileUrl);
         return ResponseEntity.ok(Response.success("Presigned URL 발급 성공", dto));
@@ -86,4 +88,4 @@ public ResponseEntity<Response<String>> editBio(
         memberService.editBio(member, requestDto.getBio());
         return ResponseEntity.ok(Response.success("소개글 수정 성공", "SUCCESS"));
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/example/FixLog/dto/s3/PresignedUploadResponseDto.java b/src/main/java/com/example/FixLog/dto/s3/PresignedUploadResponseDto.java
new file mode 100644
index 0000000..3571185
--- /dev/null
+++ b/src/main/java/com/example/FixLog/dto/s3/PresignedUploadResponseDto.java
@@ -0,0 +1,12 @@
+package com.example.FixLog.dto.s3;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+
+@Getter
+@AllArgsConstructor
+public class PresignedUploadResponseDto {
+    private String presignedUrl;  // PUT 요청용 presigned URL
+    private String fileUrl;       // 업로드 완료 후 접근 가능한 S3 URL
+}
+
diff --git a/src/main/java/com/example/FixLog/service/MainPageService.java b/src/main/java/com/example/FixLog/service/MainPageService.java
index b8cd9e2..3b27b2d 100644
--- a/src/main/java/com/example/FixLog/service/MainPageService.java
+++ b/src/main/java/com/example/FixLog/service/MainPageService.java
@@ -30,7 +30,7 @@ public MainPageService(PostRepository postRepository, MemberService memberServic
     // 이미지 null일 때 default 사진으로 변경 (프로필 사진,
     public String getDefaultImage(String image){
         String imageUrl = (image == null || image.isBlank())
-                ? "https://example.com/default-cover-image.png" : image;
+                ? "https://fixlog-bucket.s3.ap-northeast-2.amazonaws.com/default/profile.png" : image;
         System.out.println(imageUrl);
         return imageUrl;
     }
diff --git a/src/main/java/com/example/FixLog/service/PostService.java b/src/main/java/com/example/FixLog/service/PostService.java
index d10bcd6..da8b4cc 100644
--- a/src/main/java/com/example/FixLog/service/PostService.java
+++ b/src/main/java/com/example/FixLog/service/PostService.java
@@ -57,7 +57,7 @@ public PostService(PostRepository postRepository, PostLikeRepository postLikeRep
     // 이미지 null일 때 default 사진으로 변경 (프로필 사진,
     public String getDefaultImage(String image){
         String imageUrl = (image == null || image.isBlank())
-                ? "https://example.com/default-cover-image.png" : image;
+                ? "https://fixlog-bucket.s3.ap-northeast-2.amazonaws.com/default/profile.png" : image;
         System.out.println(imageUrl);
         return imageUrl;
     }
diff --git a/src/main/java/com/example/FixLog/service/S3Service.java b/src/main/java/com/example/FixLog/service/S3Service.java
index afd6158..5af4290 100644
--- a/src/main/java/com/example/FixLog/service/S3Service.java
+++ b/src/main/java/com/example/FixLog/service/S3Service.java
@@ -4,6 +4,7 @@
 import com.amazonaws.services.s3.AmazonS3;
 import com.amazonaws.services.s3.model.GeneratePresignedUrlRequest;
 import com.amazonaws.services.s3.model.ObjectMetadata;
+import com.example.FixLog.dto.s3.PresignedUploadResponseDto;
 import com.example.FixLog.exception.CustomException;
 import com.example.FixLog.exception.ErrorCode;
 import lombok.RequiredArgsConstructor;
@@ -46,7 +47,7 @@ public String generateKey(String dirName, String filename) {
         return dirName + "/" + UUID.randomUUID() + "_" + filename;
     }
 
-    public String generatePresignedUrl(String dirName, String filename, int minutes) {
+    public PresignedUploadResponseDto generatePresignedUploadUrl(String dirName, String filename, int minutes) {
         String key = generateKey(dirName, filename);
         Date expiration = new Date(System.currentTimeMillis() + minutes * 60L * 1000L);
 
@@ -55,10 +56,11 @@ public String generatePresignedUrl(String dirName, String filename, int minutes)
                 .withExpiration(expiration);
 
         URL url = amazonS3.generatePresignedUrl(request);
-        return url.toString();
+
+        return new PresignedUploadResponseDto(url.toString(), getObjectUrl(key));
     }
 
     public String getObjectUrl(String key) {
         return amazonS3.getUrl(bucket, key).toString();
     }
-}
\ No newline at end of file
+}
diff --git a/src/main/java/com/example/FixLog/util/DefaultImage.java b/src/main/java/com/example/FixLog/util/DefaultImage.java
index fa1fd90..701b2af 100644
--- a/src/main/java/com/example/FixLog/util/DefaultImage.java
+++ b/src/main/java/com/example/FixLog/util/DefaultImage.java
@@ -1,5 +1,5 @@
 package com.example.FixLog.util;
 
 public class DefaultImage {
-    public static final String PROFILE = "https://dummyimage.com/200x200/cccccc/ffffff&text=Profile"; // 임시 기본 프로필 이미지
+    public static final String PROFILE = "https://fixlog-bucket.s3.ap-northeast-2.amazonaws.com/default/profile.png";
 }