diff --git a/src/main/java/com/writon/admin/domain/controller/OrganizationController.java b/src/main/java/com/writon/admin/domain/controller/OrganizationController.java
index 88ccaa7..7d199b8 100644
--- a/src/main/java/com/writon/admin/domain/controller/OrganizationController.java
+++ b/src/main/java/com/writon/admin/domain/controller/OrganizationController.java
@@ -30,7 +30,7 @@ public class OrganizationController {
   private final ImageService imageService;
   private final TokenUtil tokenUtil;
 
-  private static final String DEFAULT_LOGO_URL = "https://writon-data.s3.ap-northeast-2.amazonaws.com/logo/default-logo.png";
+  private static final String DEFAULT_LOGO_URL = "https://writon-data2.s3.ap-northeast-2.amazonaws.com/logo/d4fdaf92-eb71-4f3a-979e-75211814d364.png";
 
   @PostMapping
   public SuccessDto<CreateOrganizationResponseDto> createOrganization(
diff --git a/src/main/java/com/writon/admin/domain/service/ImageService.java b/src/main/java/com/writon/admin/domain/service/ImageService.java
index f671e1e..c8ea07a 100644
--- a/src/main/java/com/writon/admin/domain/service/ImageService.java
+++ b/src/main/java/com/writon/admin/domain/service/ImageService.java
@@ -4,16 +4,16 @@
 import com.amazonaws.services.s3.model.CannedAccessControlList;
 import com.amazonaws.services.s3.model.ObjectMetadata;
 import com.amazonaws.services.s3.model.PutObjectRequest;
-import com.writon.admin.domain.entity.organization.Organization;
-import com.writon.admin.domain.repository.organization.PositionRepository;
 import com.writon.admin.domain.util.TokenUtil;
 import com.writon.admin.global.error.CustomException;
 import com.writon.admin.global.error.ErrorCode;
 import java.io.IOException;
+import java.util.Objects;
 import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 import org.springframework.web.multipart.MultipartFile;
+import java.util.UUID;
 
 @Service
 @RequiredArgsConstructor
@@ -33,7 +33,11 @@ public String uploadImage(MultipartFile file) {
     metadata.setContentType(file.getContentType());
     metadata.setSSEAlgorithm(ObjectMetadata.AES_256_SERVER_SIDE_ENCRYPTION);
 
-    String fileName = "logo/" + file.getOriginalFilename();
+    // 2. 파일명 생성
+    String uuid = UUID.randomUUID().toString();
+    String[] parts = Objects.requireNonNull(file.getOriginalFilename()).split("\\.");
+    String extension = parts[parts.length - 1];
+    String fileName = "logo/" + uuid + "." + extension;
 
     // 2. Amazon S3에 이미지 등록
     try {