diff --git a/src/main/java/com/moneymong/global/security/oauth/handler/KakaoService.java b/src/main/java/com/moneymong/global/security/oauth/handler/KakaoService.java
index e889907..9687b9e 100644
--- a/src/main/java/com/moneymong/global/security/oauth/handler/KakaoService.java
+++ b/src/main/java/com/moneymong/global/security/oauth/handler/KakaoService.java
@@ -1,5 +1,8 @@
 package com.moneymong.global.security.oauth.handler;
 
+import com.moneymong.domain.user.entity.User;
+import com.moneymong.domain.user.repository.UserRepository;
+import com.moneymong.global.exception.custom.NotFoundException;
 import com.moneymong.global.exception.enums.ErrorCode;
 import com.moneymong.global.security.oauth.dto.KakaoUserData;
 import com.moneymong.global.security.oauth.dto.OAuthUserDataRequest;
@@ -11,6 +14,8 @@
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.*;
 import org.springframework.stereotype.Component;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
 import org.springframework.web.client.RestClientException;
 import org.springframework.web.client.RestClientResponseException;
 import org.springframework.web.client.RestTemplate;
@@ -21,10 +26,14 @@
 public class KakaoService implements OAuthAuthenticationHandler {
 
     private final RestTemplate restTemplate;
+    private final UserRepository userRepository;
 
     @Value("${spring.security.oauth2.kakao.host}")
     private String host;
 
+    @Value("${spring.security.oauth2.kakao.admin-key}")
+    private String adminKey;
+
     @Override
     public OAuthProvider getAuthProvider() {
         return OAuthProvider.KAKAO;
@@ -70,6 +79,39 @@ public OAuthUserDataResponse getOAuthUserData(OAuthUserDataRequest request) {
 
     @Override
     public void unlink(Long userId) {
+        String oauthId = userRepository.findById(userId)
+                .orElseThrow(() -> new NotFoundException(ErrorCode.USER_NOT_FOUND))
+                .getOauthId();
+
+        String url = host + "/v1/user/unlink";
+
+        HttpHeaders httpHeaders = new HttpHeaders();
+        httpHeaders.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+        httpHeaders.add("Authorization", "KakaoAK " + adminKey);
+
+        MultiValueMap<String, String> body = new LinkedMultiValueMap<>();
+        body.add("target_id_type", "user_id");
+        body.add("target_id", oauthId);
 
+        HttpEntity<?> httpRequest = new HttpEntity<>(body, httpHeaders);
+
+        try {
+            ResponseEntity<KakaoUserData> response = restTemplate.exchange(
+                    url,
+                    HttpMethod.POST,
+                    httpRequest,
+                    KakaoUserData.class
+            );
+            assert response.getBody() != null;
+
+        } catch (RestClientException e) {
+            log.warn("[KakaoService] failed to unlink User = {}", oauthId);
+
+            if (e instanceof RestClientResponseException) {
+                throw new HttpClientException(ErrorCode.INVALID_OAUTH_TOKEN);
+            }
+
+            throw new HttpClientException(ErrorCode.HTTP_CLIENT_REQUEST_FAILED);
+        }
     }
 }
diff --git a/src/main/resources/application-dev.yml b/src/main/resources/application-dev.yml
index 0659603..7f72306 100644
--- a/src/main/resources/application-dev.yml
+++ b/src/main/resources/application-dev.yml
@@ -11,6 +11,7 @@ spring:
     oauth2:
       kakao:
         host: https://kapi.kakao.com
+        admin-key: ${KAKAO_ADMIN_KEY}
       apple:
         host: https://appleid.apple.com
         grant-type: authorization_code
diff --git a/src/main/resources/application-prod.yml b/src/main/resources/application-prod.yml
index 0659603..7f72306 100644
--- a/src/main/resources/application-prod.yml
+++ b/src/main/resources/application-prod.yml
@@ -11,6 +11,7 @@ spring:
     oauth2:
       kakao:
         host: https://kapi.kakao.com
+        admin-key: ${KAKAO_ADMIN_KEY}
       apple:
         host: https://appleid.apple.com
         grant-type: authorization_code