diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/advertisement/persistence/repository/AdCampaignRepository.java b/src/main/java/com/whereyouad/WhereYouAd/domains/advertisement/persistence/repository/AdCampaignRepository.java
index 1313bd2c..90c33bd9 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/advertisement/persistence/repository/AdCampaignRepository.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/advertisement/persistence/repository/AdCampaignRepository.java
@@ -69,4 +69,15 @@ Long sumBudgetsByUserIdAndOrgIdAndProvider(@Param("userId") Long userId, @Param(
     Optional<AdCampaign> findByExternalCampaignIdAndPlatformAccount(String externalCampaignId, PlatformAccount platformAccount);
 
     Optional<AdCampaign> findByPlatformAccountAndExternalCampaignId(PlatformAccount platformAccount, String externalCampaignId);
+
+    // PlatformAccount 연동 해제 시 사용
+    List<AdCampaign> findByPlatformAccount(PlatformAccount platformAccount);
+
+    // 연동 해제 후 빈 Project 정리 대상 식별용 (project null 인 AdCampaign 은 제외)
+    @Query("SELECT DISTINCT c.project.id FROM AdCampaign c " +
+            "WHERE c.platformAccount.id = :platformAccountId AND c.project IS NOT NULL")
+    List<Long> findDistinctProjectIdsByPlatformAccountId(@Param("platformAccountId") Long platformAccountId);
+
+    // 특정 Project 에 남아있는 AdCampaign 수 (빈 Project 판단용)
+    long countByProject_Id(Long projectId);
 }
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/advertisement/persistence/repository/MetricFactRepository.java b/src/main/java/com/whereyouad/WhereYouAd/domains/advertisement/persistence/repository/MetricFactRepository.java
index a4d18310..95fe1130 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/advertisement/persistence/repository/MetricFactRepository.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/advertisement/persistence/repository/MetricFactRepository.java
@@ -10,6 +10,7 @@
 import com.whereyouad.WhereYouAd.domains.advertisement.persistence.repository.projection.RoasProjection;
 import com.whereyouad.WhereYouAd.domains.project.application.dto.ProjectQueryDto;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
 import org.springframework.data.repository.query.Param;
 
@@ -227,4 +228,17 @@ Optional<MetricFact> findByAdContentAndTimeBucketAndGrain(
     );
 
     Optional<MetricFact> findByPlatformAccount_IdAndAdContent_IdAndTimeBucket(Long platformAccountId, Long adContentId, LocalDateTime timeBucket);
+
+    // PlatformAccount 연동 해제 시 청크 단위 정리용
+    @Modifying
+    @Query(value = "DELETE FROM metric_fact " +
+            "WHERE platform_account_id = :platformAccountId " +
+            "LIMIT :batchSize",
+            nativeQuery = true)
+    int deleteByPlatformAccountIdInBatch(
+            @Param("platformAccountId") Long platformAccountId,
+            @Param("batchSize") int batchSize
+    );
+
+    long countByProject_Id(Long projectId);
 }
\ No newline at end of file
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/click/persistence/repository/ClickLogRepository.java b/src/main/java/com/whereyouad/WhereYouAd/domains/click/persistence/repository/ClickLogRepository.java
index 298396f9..a6144e7a 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/click/persistence/repository/ClickLogRepository.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/click/persistence/repository/ClickLogRepository.java
@@ -2,6 +2,26 @@
 
 import com.whereyouad.WhereYouAd.domains.click.persistence.entity.ClickLog;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
 public interface ClickLogRepository extends JpaRepository<ClickLog, Long> {
-}
+
+    // PlatformAccount 연동 해제 시 청크 단위 정리용
+    // ad_content_id → ad_group_id → ad_campaign_id → platform_account_id 경유
+    @Modifying
+    @Query(value = "DELETE FROM click_log " +
+            "WHERE ad_content_id IN (" +
+            "  SELECT ac.ad_content_id FROM ad_content ac " +
+            "  JOIN ad_group ag ON ac.ad_group_id = ag.ad_group_id " +
+            "  JOIN ad_campaign camp ON ag.ad_campaign_id = camp.ad_campaign_id " +
+            "  WHERE camp.platform_account_id = :platformAccountId" +
+            ") " +
+            "LIMIT :batchSize",
+            nativeQuery = true)
+    int deleteByPlatformAccountIdInBatch(
+            @Param("platformAccountId") Long platformAccountId,
+            @Param("batchSize") int batchSize
+    );
+}
\ No newline at end of file
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/organization/domain/service/OrgService.java b/src/main/java/com/whereyouad/WhereYouAd/domains/organization/domain/service/OrgService.java
index c4b1546a..a5c883b1 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/organization/domain/service/OrgService.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/organization/domain/service/OrgService.java
@@ -24,6 +24,9 @@ public interface OrgService {
 
     void removeOrganizationSoft(Long userId, Long orgId);
 
+    // 회원 탈퇴 전용 Soft Delete - 플랫폼 연동 검증 생략 (연동 해제는 UserDeleteScheduler 가 Hard Delete 시점에 처리)
+    void removeOrganizationSoftForWithdrawal(Long orgId);
+
     // User Hard Delete 정리용 - 특정 User 가 owner 인 Soft Deleted Organization 들을 관련 엔티티와 함께 Hard Delete
     void removeOrganizationsOwnedBySoftDeletedUser(Long userId);
 
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/organization/domain/service/OrgServiceImpl.java b/src/main/java/com/whereyouad/WhereYouAd/domains/organization/domain/service/OrgServiceImpl.java
index 977ba067..224882fc 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/organization/domain/service/OrgServiceImpl.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/organization/domain/service/OrgServiceImpl.java
@@ -326,6 +326,26 @@ public void removeOrganizationSoft(Long userId, Long orgId) {
         organization.softDelete();
     }
 
+    // 회원 탈퇴 흐름 전용 Soft Delete
+    // UserService.deleteUser 내부에서 본인 단독 소유 조직을 정리할 때 사용
+    // 호출 시점에 소유자 검증은 호출부(handleOrganizationsOwnedByUser)에서 이미 완료
+    @Override
+    public void removeOrganizationSoftForWithdrawal(Long orgId) {
+        Organization organization = orgRepository.findById(orgId)
+                .orElseThrow(() -> new OrgHandler(OrgErrorCode.ORG_NOT_FOUND));
+
+        // 현재 워크스페이스가 삭제되는 조직인 멤버들의 currentOrgId를 null로 초기화
+        List<OrgMember> orgMembers = orgMemberRepository.findOrgMemberByOrg(organization);
+        for (OrgMember member : orgMembers) {
+            if (Objects.equals(member.getUser().getCurrentOrgId(), orgId)) {
+                member.getUser().setCurrentOrgId(null);
+            }
+        }
+
+        // 조직 status 만 DELETED 로 변경
+        organization.softDelete();
+    }
+
     // User Hard Delete 정리용 - 해당 User 가 owner 인 Soft Deleted Organization 들을 Hard Delete
     // (Soft Delete 시 'owner + 다른 멤버 존재' 케이스는 차단되므로, 여기서는 본인 1명만 속한 조직만 존재)
     @Override
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/PlatformService.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/PlatformService.java
index 4035b370..c4a82502 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/PlatformService.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/PlatformService.java
@@ -12,4 +12,6 @@ public interface PlatformService {
 
     void disconnectPlatform(Long userId, Long orgId, Long accountId);
 
+    // 회원 탈퇴 스케줄러 등 시스템 내부 호출용 - 요청자 권한 검증 없이 계정 단위 연동 해제
+    void disconnectAccountBySystem(Long accountId);
 }
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/PlatformServiceImpl.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/PlatformServiceImpl.java
index 837f835b..ec830c59 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/PlatformServiceImpl.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/PlatformServiceImpl.java
@@ -8,6 +8,8 @@
 import com.whereyouad.WhereYouAd.domains.platform.application.dto.request.PlatformRequest;
 import com.whereyouad.WhereYouAd.domains.platform.application.dto.response.PlatformResponse;
 import com.whereyouad.WhereYouAd.domains.platform.application.mapper.PlatformConverter;
+import com.whereyouad.WhereYouAd.domains.platform.domain.constant.PlatformStatus;
+import com.whereyouad.WhereYouAd.domains.platform.domain.service.scheduler.PlatformDataCleanupExecutor;
 import com.whereyouad.WhereYouAd.domains.platform.exception.PlatformHandler;
 import com.whereyouad.WhereYouAd.domains.platform.exception.code.PlatformErrorCode;
 import com.whereyouad.WhereYouAd.domains.platform.persistence.entity.PlatformAccount;
@@ -27,6 +29,7 @@
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
 
 import java.util.List;
@@ -42,6 +45,7 @@ public class PlatformServiceImpl implements PlatformService {
     private final OrgMemberRepository orgMemberRepository;
     private final PlatformAccountRepository platformAccountRepository;
     private final PlatformConnectionRepository platformConnectionRepository;
+    private final PlatformDataCleanupExecutor platformDataCleanupExecutor;
     private final NaverClient naverClient;
     private final NaverAdAuthStrategy naverAdAuthStrategy;
 
@@ -102,8 +106,10 @@ public PlatformResponse.PlatformAccountListResponse getPlatformSyncInfos(Long us
             throw new PlatformHandler(PlatformErrorCode.PLATFORM_FORBIDDEN);
         }
 
-        // userId, orgId 기반 PlatformConnection 모두 조회
-        List<PlatformConnection> connections = platformConnectionRepository.findByUserIdAndOrgId(userId, orgId);
+        // userId, orgId 기반 PlatformConnection 조회 (삭제 대기(DISCONNECTED) 계정은 이미 해제된 것으로 보고 제외)
+        List<PlatformConnection> connections = platformConnectionRepository.findByUserIdAndOrgId(userId, orgId).stream()
+                .filter(connection -> connection.getPlatformAccount().getStatus() != PlatformStatus.DISCONNECTED)
+                .toList();
 
         // DTO 로 변환 및 반환
         return PlatformConverter.toPlatformAccountListResponse(connections);
@@ -144,10 +150,75 @@ public PlatformResponse.PlatformAccount updateNaverAdAccount(Long userId, Long o
         return PlatformConverter.toPlatformAccountResponse(platformAccount);
     }
 
+    // 광고 플랫폼 연동 해제 (수동 요청)
+    // 권한/소유자 검증 후 상태만 DISCONNECTED 로 변경하고 즉시 반환, 실제 데이터 삭제는 PlatformAccountCleanupScheduler 에서 비동기 진행
     @Override
     public void disconnectPlatform(Long userId, Long orgId, Long accountId) {
-        // TODO: 관련된 PlatformConnection, PlatformAccount, 광고 도메인 엔티티 제거 로직 개발
-        return;
+        // 검증 로직
+        userRepository.findById(userId)
+                .orElseThrow(() -> new UserHandler(UserErrorCode.USER_NOT_FOUND));
+
+        OrgMember orgMember = orgMemberRepository.findByUserIdAndOrgId(userId, orgId)
+                .orElseThrow(() -> new PlatformHandler(PlatformErrorCode.PLATFORM_ORG_MEMBER_NOT_FOUND));
+
+        if (orgMember.getRole() != OrgRole.ADMIN) {
+            throw new PlatformHandler(PlatformErrorCode.PLATFORM_FORBIDDEN);
+        }
+
+        PlatformAccount platformAccount = platformAccountRepository.findById(accountId)
+                .orElseThrow(() -> new PlatformHandler(PlatformErrorCode.PLATFORM_ACCOUNT_NOT_FOUND));
+
+        if (!platformAccount.getOrganization().getId().equals(orgId)) {
+            throw new PlatformHandler(PlatformErrorCode.PLATFORM_ACCOUNT_NOT_BELONG_TO_ORG);
+        }
+
+        // 계정 소유자(연동 주인) 검증
+        platformConnectionRepository.findByUserIdAndPlatformAccountId(userId, accountId)
+                .orElseThrow(() -> new PlatformHandler(PlatformErrorCode.PLATFORM_NOT_ACCOUNT_OWNER));
+
+        // 멱등성: 이미 삭제 대기 상태면 그대로 반환
+        if (platformAccount.getStatus() == PlatformStatus.DISCONNECTED) {
+            return;
+        }
+
+        // 상태만 DISCONNECTED 로 변경
+        platformAccount.softDelete();
+    }
+
+    // 시스템 내부 호출용 플랫폼 연동 해제 — 권한 검증 없이 계정 단위로 실제 데이터를 정리
+    // 호출처: 회원 탈퇴 스케줄러(UserDeleteScheduler), 수동 연동 해제 정리 스케줄러(PlatformAccountCleanupScheduler)
+    @Override
+    @Transactional(propagation = Propagation.NOT_SUPPORTED)
+    public void disconnectAccountBySystem(Long accountId) {
+        List<Long> projectIds = platformDataCleanupExecutor.collectProjectIds(accountId);
+        cleanupAccount(accountId, projectIds);
+    }
+
+    // 계정 단위 데이터 정리 메서드화
+    // ClickLog / MetricFact 청크 삭제 → AdCampaign + PlatformConnection + PlatformAccount 삭제 → 빈 Project 삭제
+    // 대규모 엔티티 삭제를 위해 별도 처리 클래스 (PlatformDataCleanupExecutor) 에서 Chunk 단위 삭제 처리
+    private void cleanupAccount(Long accountId, List<Long> projectIds) {
+        int chunkDeleted; // 하나의 청크 당 삭제 갯수
+        long totalClickLogDeleted = 0L; // ClickLog 전체 삭제 갯수
+        long totalMetricFactDeleted = 0L; // MetricFact 전체 삭제 갯수
+
+        // ClickLog 청크 정리 (REQUIRES_NEW)
+        do {
+            chunkDeleted = platformDataCleanupExecutor.deleteClickLogChunk(accountId);
+            totalClickLogDeleted += chunkDeleted;
+        } while (chunkDeleted > 0);
+        log.info("ClickLog 삭제 완료 - platformAccountId={}, totalCount={}", accountId, totalClickLogDeleted);
+
+        // MetricFact 청크 정리 (REQUIRES_NEW) — Project 삭제 단계에서 FK 위반 방지
+        do {
+            chunkDeleted = platformDataCleanupExecutor.deleteMetricFactChunk(accountId);
+            totalMetricFactDeleted += chunkDeleted;
+        } while (chunkDeleted > 0);
+        log.info("MetricFact 삭제 완료 - platformAccountId={}, totalCount={}", accountId, totalMetricFactDeleted);
+
+        // AdCampaign + PlatformConnection + PlatformAccount + 비어있는 Project 삭제 진행
+        // PlatformAccount 가 가장 마지막에 삭제됨 & 삭제 실패 시 전체 롤백되어 다음 회차에 재시도
+        platformDataCleanupExecutor.deleteAccountAndRelations(accountId, projectIds);
     }
 
     private void validateNaverCredentials(String customerId, String encryptedApiKey, String encryptedSecretKey) {
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/scheduler/PlatformAccountCleanupScheduler.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/scheduler/PlatformAccountCleanupScheduler.java
new file mode 100644
index 00000000..8dd365c4
--- /dev/null
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/scheduler/PlatformAccountCleanupScheduler.java
@@ -0,0 +1,45 @@
+package com.whereyouad.WhereYouAd.domains.platform.domain.service.scheduler;
+
+import com.whereyouad.WhereYouAd.domains.platform.domain.constant.PlatformStatus;
+import com.whereyouad.WhereYouAd.domains.platform.domain.service.PlatformService;
+import com.whereyouad.WhereYouAd.domains.platform.persistence.repository.PlatformAccountRepository;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class PlatformAccountCleanupScheduler {
+
+    private final PlatformAccountRepository platformAccountRepository;
+    private final PlatformService platformService;
+
+    // 수동 연동 해제(DISCONNECTED 마킹)된 PlatformAccount 의 실제 데이터 정리
+    // cleanupAccount 는 ClickLog/MetricFact/AdCampaign/Connection 먼저 삭제, PlatformAccount는 맨 마지막에 삭제
+    // TODO : 스케줄러 주기를 어떻게 할지? (현재는 새벽 4시에 실행)
+    @Scheduled(cron = "0 0 4 * * *", zone = "Asia/Seoul")
+    public void cleanupDeletedAccounts() {
+        List<Long> accountIds = platformAccountRepository.findIdsByStatus(PlatformStatus.DISCONNECTED);
+        if (accountIds.isEmpty()) {
+            return;
+        }
+        log.info("연동 해제(DISCONNECTED) 계정 정리 스케줄러 실행 - 대상 {}건", accountIds.size());
+
+        int successCount = 0;
+        for (Long accountId : accountIds) {
+            try {
+                platformService.disconnectAccountBySystem(accountId);
+                successCount++;
+            } catch (Exception e) {
+                // 한 계정의 실패가 나머지 계정 정리를 막지 않도록 격리 → 다음 회차에 재시도
+                log.error("연동 해제 계정 정리 실패 - accountId={}", accountId, e);
+            }
+        }
+
+        log.info("연동 해제(DISCONNECTED) 계정 정리 완료 - 대상 갯수: {}, 성공 갯수: {}", accountIds.size(), successCount);
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/scheduler/PlatformDataCleanupExecutor.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/scheduler/PlatformDataCleanupExecutor.java
new file mode 100644
index 00000000..4bd4931d
--- /dev/null
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/domain/service/scheduler/PlatformDataCleanupExecutor.java
@@ -0,0 +1,98 @@
+package com.whereyouad.WhereYouAd.domains.platform.domain.service.scheduler;
+
+import com.whereyouad.WhereYouAd.domains.advertisement.persistence.entity.AdCampaign;
+import com.whereyouad.WhereYouAd.domains.advertisement.persistence.repository.AdCampaignRepository;
+import com.whereyouad.WhereYouAd.domains.advertisement.persistence.repository.MetricFactRepository;
+import com.whereyouad.WhereYouAd.domains.click.persistence.repository.ClickLogRepository;
+import com.whereyouad.WhereYouAd.domains.platform.persistence.entity.PlatformAccount;
+import com.whereyouad.WhereYouAd.domains.platform.persistence.entity.PlatformConnection;
+import com.whereyouad.WhereYouAd.domains.platform.persistence.repository.PlatformAccountRepository;
+import com.whereyouad.WhereYouAd.domains.platform.persistence.repository.PlatformConnectionRepository;
+import com.whereyouad.WhereYouAd.domains.project.persistence.repository.ProjectRepository;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Propagation;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+@Slf4j
+@Component
+@RequiredArgsConstructor
+public class PlatformDataCleanupExecutor {
+
+    private static final int BATCH_SIZE = 1000;
+
+    private final PlatformAccountRepository platformAccountRepository;
+    private final PlatformConnectionRepository platformConnectionRepository;
+    private final AdCampaignRepository adCampaignRepository;
+    private final ProjectRepository projectRepository;
+    private final ClickLogRepository clickLogRepository;
+    private final MetricFactRepository metricFactRepository;
+
+    // 삭제에 영향받는 projectId 수집 (수동 연동 해제 정리 / 회원 탈퇴 스케줄러 등 시스템 내부 호출용)
+    @Transactional(readOnly = true)
+    public List<Long> collectProjectIds(Long accountId) {
+        return adCampaignRepository.findDistinctProjectIdsByPlatformAccountId(accountId);
+    }
+
+    // 청크 단위로 ClickLog 삭제 — 메인 트랜잭션과 분리
+    @Transactional(propagation = Propagation.REQUIRES_NEW)
+    public int deleteClickLogChunk(Long platformAccountId) {
+        int deleted = clickLogRepository.deleteByPlatformAccountIdInBatch(platformAccountId, BATCH_SIZE);
+        if (deleted > 0) {
+            log.debug("ClickLog 청크 삭제 - platformAccountId={}, deleted={}", platformAccountId, deleted);
+        }
+        return deleted;
+    }
+
+    // 청크 단위로 MetricFact 삭제
+    @Transactional(propagation = Propagation.REQUIRES_NEW)
+    public int deleteMetricFactChunk(Long platformAccountId) {
+        int deleted = metricFactRepository.deleteByPlatformAccountIdInBatch(platformAccountId, BATCH_SIZE);
+        if (deleted > 0) {
+            log.debug("MetricFact 청크 삭제 - platformAccountId={}, deleted={}", platformAccountId, deleted);
+        }
+        return deleted;
+    }
+
+    // AdCampaign + PlatformConnection + PlatformAccount + 비어있는 Project 원자적 삭제
+    @Transactional
+    public void deleteAccountAndRelations(Long accountId, List<Long> projectIds) {
+        PlatformAccount platformAccount = platformAccountRepository.findById(accountId)
+                .orElse(null);
+
+        if (platformAccount == null) {
+            log.info("이미 삭제된 PlatformAccount - accountId={}, 정리 skip", accountId);
+            return;
+        }
+
+        // AdCampaign 제거
+        List<AdCampaign> campaigns = adCampaignRepository.findByPlatformAccount(platformAccount);
+        if (!campaigns.isEmpty()) {
+            adCampaignRepository.deleteAll(campaigns);
+            adCampaignRepository.flush();
+            // AdCampaign 삭제 시 CascadeType.ALL 로 인해 연관된 AdGroup, AdContent 도 함께 제거됨
+        }
+
+        // PlatformConnection 제거
+        List<PlatformConnection> connections = platformConnectionRepository.findAllByPlatformAccount_Id(accountId);
+        if (!connections.isEmpty()) {
+            platformConnectionRepository.deleteAll(connections);
+            platformConnectionRepository.flush();
+        }
+
+        // 빈 Project 제거
+        for (Long projectId : projectIds) {
+            if (adCampaignRepository.countByProject_Id(projectId) == 0 &&
+                    metricFactRepository.countByProject_Id(projectId) == 0)
+            {
+                projectRepository.deleteById(projectId);
+            }
+        }
+
+        // PlatformAccount 제거
+        platformAccountRepository.delete(platformAccount);
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/exception/code/PlatformErrorCode.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/exception/code/PlatformErrorCode.java
index 8df23563..9b7b3b6f 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/exception/code/PlatformErrorCode.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/exception/code/PlatformErrorCode.java
@@ -14,6 +14,8 @@ public enum PlatformErrorCode implements BaseErrorCode {
 
     // 403
     PLATFORM_FORBIDDEN(HttpStatus.FORBIDDEN, "PLATFORM_403_1", "API키 등록은 ADMIN 권한이 필요합니다."),
+    PLATFORM_ACCOUNT_NOT_BELONG_TO_ORG(HttpStatus.FORBIDDEN, "PLATFORM_403_2", "해당 광고 계정은 요청한 조직 소속이 아닙니다."),
+    PLATFORM_NOT_ACCOUNT_OWNER(HttpStatus.FORBIDDEN, "PLATFORM_403_3", "본인이 등록한 광고 계정만 연동 해제할 수 있습니다."),
 
     // 404
     PLATFORM_CONNECTION_NOT_FOUND(HttpStatus.NOT_FOUND, "PLATFORM_404_1", "조직과 연결된 인증 정보를 찾을 수 없습니다."),
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/entity/PlatformAccount.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/entity/PlatformAccount.java
index 9c2ae2a6..04640c53 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/entity/PlatformAccount.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/entity/PlatformAccount.java
@@ -52,4 +52,9 @@ public class PlatformAccount extends BaseEntity {
     @JoinColumn(name = "org_id")
     private Organization organization;
 
+    // 수동 연동 해제 요청 시 상태만 DISCONNECTED 로 변경 (실제 데이터 정리는 스케줄러가 수행)
+    public void softDelete() {
+        this.status = PlatformStatus.DISCONNECTED;
+    }
+
 }
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/repository/PlatformAccountRepository.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/repository/PlatformAccountRepository.java
index 7394ab45..a4c6dd51 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/repository/PlatformAccountRepository.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/repository/PlatformAccountRepository.java
@@ -2,12 +2,21 @@
 
 import com.whereyouad.WhereYouAd.domains.advertisement.domain.constant.Provider;
 import com.whereyouad.WhereYouAd.domains.organization.persistence.entity.Organization;
+import com.whereyouad.WhereYouAd.domains.platform.domain.constant.PlatformStatus;
 import com.whereyouad.WhereYouAd.domains.platform.persistence.entity.PlatformAccount;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 
+import java.util.List;
 import java.util.Optional;
 
 public interface PlatformAccountRepository extends JpaRepository<PlatformAccount, Long> {
+
+    // DISCONNECTED 인 PlatformAccount id 목록 조회 (연동 해제 정리 스케줄러용)
+    @Query("SELECT pa.id FROM PlatformAccount pa WHERE pa.status = :status")
+    List<Long> findIdsByStatus(@Param("status") PlatformStatus status);
+
     Optional<PlatformAccount> findByExternalAccountIdAndProviderAndOrganization_Id(String externalAccountId, Provider provider, Long orgId);
 
     // 계정이 존재하는지 확인
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/repository/PlatformConnectionRepository.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/repository/PlatformConnectionRepository.java
index c58e3004..7c8ff59f 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/repository/PlatformConnectionRepository.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/persistence/repository/PlatformConnectionRepository.java
@@ -24,9 +24,6 @@ public interface PlatformConnectionRepository extends JpaRepository<PlatformConn
     // 조직 ID와 플랫폼으로 등록된 연동 정보(Account/Connection) 목록 조회
     List<PlatformConnection> findByPlatformAccount_Organization_IdAndPlatformAccount_Provider(Long orgId, Provider provider);
 
-    // 사용자 ID로 등록된 연동 정보 목록 조회 (회원 탈퇴 시 정리용)
-    List<PlatformConnection> findByUser_Id(Long userId);
-
     // 사용자 ID와 플랫폼으로 등록된 연동 정보 목록 조회
     List<PlatformConnection> findByUser_IdAndPlatformAccount_Provider(Long userId, Provider provider);
 
@@ -43,4 +40,11 @@ public interface PlatformConnectionRepository extends JpaRepository<PlatformConn
             "JOIN FETCH c.platformAccount pa " +
             "WHERE c.user.id = :userId AND pa.organization.id = :orgId")
     List<PlatformConnection> findByUserIdAndOrgId(@Param("userId") Long userId, @Param("orgId") Long orgId);
+
+    // PlatformAccount 연동 해제 시 해당 계정에 연결된 모든 connection 일괄 삭제를 위한 List 조회
+    List<PlatformConnection> findAllByPlatformAccount_Id(Long platformAccountId);
+
+    // 회원 Hard Delete 시 해당 유저가 연동한 PlatformAccount id 목록 조회 (시스템 자동 연동 해제용)
+    @Query("SELECT DISTINCT c.platformAccount.id FROM PlatformConnection c WHERE c.user.id = :userId")
+    List<Long> findDistinctAccountIdsByUserId(@Param("userId") Long userId);
 }
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/presentation/PlatformController.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/presentation/PlatformController.java
index d223a633..35ade7c5 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/presentation/PlatformController.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/presentation/PlatformController.java
@@ -5,7 +5,6 @@
 import com.whereyouad.WhereYouAd.domains.platform.domain.service.PlatformService;
 import com.whereyouad.WhereYouAd.domains.platform.presentation.docs.PlatformControllerDocs;
 import com.whereyouad.WhereYouAd.global.response.DataResponse;
-import io.swagger.v3.oas.annotations.Hidden;
 import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
@@ -61,8 +60,6 @@ public ResponseEntity<DataResponse<PlatformResponse.PlatformAccount>> updateNave
         );
     }
 
-
-    @Hidden
     @DeleteMapping("/{orgId}/accounts/{accountId}")
     public ResponseEntity<DataResponse<String>> disconnectPlatform(
             @AuthenticationPrincipal(expression = "userId") Long userId,
@@ -72,7 +69,7 @@ public ResponseEntity<DataResponse<String>> disconnectPlatform(
     {
         platformService.disconnectPlatform(userId, orgId, accountId);
 
-        return ResponseEntity.ok(DataResponse.from("광고 플랫폼 연동 정보와 연관된 광고 정보가 정상적으로 삭제되었습니다."));
+        return ResponseEntity.ok(DataResponse.from("광고 플랫폼 연동 해제 요청이 접수되었습니다. 연관된 광고 데이터는 잠시 후 자동으로 정리됩니다."));
     }
 
 }
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/presentation/docs/PlatformControllerDocs.java b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/presentation/docs/PlatformControllerDocs.java
index cb911746..a8c698b5 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/platform/presentation/docs/PlatformControllerDocs.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/platform/presentation/docs/PlatformControllerDocs.java
@@ -66,4 +66,28 @@ ResponseEntity<DataResponse<PlatformResponse.PlatformAccount>> updateNaverAdAcco
             @PathVariable Long orgId,
             @RequestBody PlatformRequest.PlatformAccount request
     );
+
+    @Operation(
+            summary = "광고 플랫폼 계정 연동 해제 API",
+            description = "본인이 등록한 광고 플랫폼 계정의 연동을 해제합니다. \n\n" +
+                    "요청 시점에는 계정 상태만 '삭제 대기(DISCONNECTED)'로 변경하고 즉시 응답하며, " +
+                    "해당 계정에 종속된 모든 광고 데이터(ClickLog/MetricFact/AdCampaign/Connection/빈 Project)는 " +
+                    "스케줄러가 비동기로 정리합니다.\n\n" +
+                    "**주의** : 삭제한 플랫폼 계정에 관련된 모든 광고 데이터가 삭제되며, 복구 불가합니다. 사용자에게 안내 필요\n\n" +
+                    "ADMIN 권한을 가진 조직 멤버 중 본인이 직접 등록한(광고 플랫폼 연동을 진행한 회원 본인만) 계정만 해제할 수 있습니다."
+    )
+    @ApiResponses({
+            @ApiResponse(responseCode = "200", description = "연동 해제 요청 접수 성공 (실제 데이터 정리는 비동기 수행)"),
+            @ApiResponse(responseCode = "403_1", description = "PLATFORM_403_1 - ADMIN 권한 없음"),
+            @ApiResponse(responseCode = "403_2", description = "PLATFORM_403_2 - 해당 광고 계정이 요청한 조직 소속이 아님"),
+            @ApiResponse(responseCode = "403_3", description = "PLATFORM_403_3 - 본인이 등록한 광고 계정이 아님"),
+            @ApiResponse(responseCode = "404_1", description = "USER_404_1 - 회원 정보를 찾을 수 없음"),
+            @ApiResponse(responseCode = "404_2", description = "PLATFORM_404_2 - 해당 조직의 멤버가 아님"),
+            @ApiResponse(responseCode = "404_3", description = "PLATFORM_404_3 - 해당 광고 계정을 찾을 수 없음")
+    })
+    ResponseEntity<DataResponse<String>> disconnectPlatform(
+            @AuthenticationPrincipal(expression = "userId") Long userId,
+            @PathVariable(value = "orgId") Long orgId,
+            @PathVariable(value = "accountId") Long accountId
+    );
 }
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/user/domain/service/UserService.java b/src/main/java/com/whereyouad/WhereYouAd/domains/user/domain/service/UserService.java
index 742bb1a7..62134a5b 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/user/domain/service/UserService.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/user/domain/service/UserService.java
@@ -5,8 +5,6 @@
 import com.whereyouad.WhereYouAd.domains.organization.persistence.entity.Organization;
 import com.whereyouad.WhereYouAd.domains.organization.persistence.repository.OrgInvitationRepository;
 import com.whereyouad.WhereYouAd.domains.organization.persistence.repository.OrgMemberRepository;
-import com.whereyouad.WhereYouAd.domains.platform.persistence.entity.PlatformConnection;
-import com.whereyouad.WhereYouAd.domains.platform.persistence.repository.PlatformConnectionRepository;
 import com.whereyouad.WhereYouAd.domains.user.application.dto.request.UserInfoModifyRequest;
 import com.whereyouad.WhereYouAd.domains.user.application.dto.response.MyOrgResponse;
 import com.whereyouad.WhereYouAd.domains.user.application.dto.response.MyPageResponse;
@@ -43,7 +41,6 @@ public class UserService {
     private final OrgMemberRepository orgMemberRepository;
     private final OrgInvitationRepository orgInvitationRepository;
     private final RefreshTokenRepository refreshTokenRepository;
-    private final PlatformConnectionRepository platformConnectionRepository;
     private final OrgService orgService;
     private final PasswordEncoder passwordEncoder;
     private final RedisUtil redisUtil;
@@ -217,9 +214,8 @@ public void deleteUser(Long userId) {
                 .orElseThrow(() -> new UserHandler(UserErrorCode.USER_NOT_FOUND));
 
         // 1) 검증 단계
-        // PlatformConnection 이 연결되어있는가? -> 연결되어 있으면 오류
         // 속한 Organization 중에 "해당 회원이 owner 인데 다른 회원이 멤버로 속한 Organization" 이 존재하는가? -> 존재 시 오류
-        validateNoPlatformConnections(userId);
+        // 광고 플랫폼 연동 존재 여부가 회원 탈퇴를 막지 않음 -> UserDeleteScheduler 가 Hard Delete 시점에 자동 해제
         handleOrganizationsOwnedByUser(userId);
 
         // 2) 즉시 정리 단계
@@ -232,14 +228,6 @@ public void deleteUser(Long userId) {
         user.softDeleteUser();
     }
 
-    // 광고 플랫폼 연동 정보 존재 시 탈퇴 불가
-    private void validateNoPlatformConnections(Long userId) {
-        List<PlatformConnection> platformConnections = platformConnectionRepository.findByUser_Id(userId);
-        if (!platformConnections.isEmpty()) {
-            throw new UserHandler(UserErrorCode.USER_HAS_PLATFORM_CONNECTION);
-        }
-    }
-
     // 회원이 owner 인 조직 처리 - 다른 멤버가 있으면 탈퇴 거부, 본인만 있으면 Soft Delete
     private void handleOrganizationsOwnedByUser(Long userId) {
         List<OrgMember> orgMembers = orgMemberRepository.findOrgMemberByUserId(userId);
@@ -256,9 +244,9 @@ private void handleOrganizationsOwnedByUser(Long userId) {
                 throw new UserHandler(UserErrorCode.USER_OWNS_ORGANIZATION);
             }
 
-            // 본인만 속한 조직은 OrgService 의 Soft Delete 로직 호출
+            // 본인만 속한 조직은 OrgService 의 회원 탈퇴 전용 Soft Delete 로직 호출
             // 추후 Scheduler 에서 해당 Organization 과 연관 엔티티 한번에 정리
-            orgService.removeOrganizationSoft(userId, organization.getId());
+            orgService.removeOrganizationSoftForWithdrawal(organization.getId());
         }
     }
 
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/user/domain/service/scheduler/UserDeleteScheduler.java b/src/main/java/com/whereyouad/WhereYouAd/domains/user/domain/service/scheduler/UserDeleteScheduler.java
index f4a8c374..a989b972 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/user/domain/service/scheduler/UserDeleteScheduler.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/user/domain/service/scheduler/UserDeleteScheduler.java
@@ -1,5 +1,7 @@
 package com.whereyouad.WhereYouAd.domains.user.domain.service.scheduler;
 
+import com.whereyouad.WhereYouAd.domains.platform.domain.service.PlatformService;
+import com.whereyouad.WhereYouAd.domains.platform.persistence.repository.PlatformConnectionRepository;
 import com.whereyouad.WhereYouAd.domains.user.domain.constant.UserStatus;
 import com.whereyouad.WhereYouAd.domains.user.persistence.repository.UserRepository;
 import lombok.RequiredArgsConstructor;
@@ -19,6 +21,8 @@ public class UserDeleteScheduler {
 
     private final UserRepository userRepository;
     private final UserDeleteExecutor userDeleteExecutor;
+    private final PlatformConnectionRepository platformConnectionRepository;
+    private final PlatformService platformService;
 
     // 매일 새벽 3시
     @Scheduled(cron = "0 0 3 * * *", zone = "Asia/Seoul")
@@ -33,6 +37,28 @@ public void hardDeleteUsers() {
         int successCount = 0;
         for (Long userId : targetUserIds) {
             try {
+                // 광고 플랫폼 연동 자동 해제 (계정 + 연관 광고 엔티티/ClickLog/MetricFact/비어있는 Project 정리)
+                // PlatformAccount → Organization FK 위반 방지를 위해 조직 Hard Delete 전에 수행
+                List<Long> accountIds = platformConnectionRepository.findDistinctAccountIdsByUserId(userId);
+
+                boolean isAllCleaned = true;
+                for (Long accountId : accountIds) {
+                    try {
+                        platformService.disconnectAccountBySystem(accountId);
+                    } catch (Exception e) {
+                        // 광고계정 하나에서 실패가 나머지 계정/회원 삭제 진행을 막지 않도록 격리 -> 다음 광고 게정 계속
+                        isAllCleaned = false;
+                        log.error("플랫폼 계정 정리 실패 - userId={}, accountId={}", userId, accountId, e);
+                    }
+                }
+
+                // 삭제 실패한 계정이 하나라도 남아있으면 Organization Hard Delete 시 FK 위반 -> 이번 회차에선 보류, 다음 회차에 재시도
+                if (!isAllCleaned) {
+                    log.warn("플랫폼 계정 정리 미완료이므로 Hard Delete 보류 - userId={}", userId);
+                    continue;
+                }
+
+                // 회원/조직/멤버 Hard Delete
                 userDeleteExecutor.hardDeleteSingleUser(userId);
                 successCount++;
             } catch (Exception e) {
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/user/exception/code/UserErrorCode.java b/src/main/java/com/whereyouad/WhereYouAd/domains/user/exception/code/UserErrorCode.java
index a9508020..310d031b 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/user/exception/code/UserErrorCode.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/user/exception/code/UserErrorCode.java
@@ -18,7 +18,6 @@ public enum UserErrorCode implements BaseErrorCode {
     SOCIAL_USER_PASSWORD_CANNOT_MODIFY(HttpStatus.BAD_REQUEST, "USER_400_7", "소셜 로그인 회원은 비밀번호를 변경할 수 없습니다."),
     USER_OLD_PASSWORD_REQUIRED(HttpStatus.BAD_REQUEST, "USER_400_8", "비밀번호 변경을 위해선 이전 비밀번호 입력이 필요합니다."),
     USER_OWNS_ORGANIZATION(HttpStatus.BAD_REQUEST, "USER_400_9", "다른 멤버가 속한 조직의 생성자는 탈퇴할 수 없습니다. 소유권을 위임한 뒤 다시 시도해 주세요."),
-    USER_HAS_PLATFORM_CONNECTION(HttpStatus.BAD_REQUEST, "USER_400_10", "연동된 광고 플랫폼을 먼저 연동 해제한 뒤 재시도 해주세요."),
 
     // 401
     USER_EMAIL_NOT_VERIFIED(HttpStatus.UNAUTHORIZED, "USER_401_1", "이메일 인증이 진행되지 않았습니다."),
diff --git a/src/main/java/com/whereyouad/WhereYouAd/domains/user/presentation/docs/UserControllerDocs.java b/src/main/java/com/whereyouad/WhereYouAd/domains/user/presentation/docs/UserControllerDocs.java
index 6b5fcddf..93ccdf14 100644
--- a/src/main/java/com/whereyouad/WhereYouAd/domains/user/presentation/docs/UserControllerDocs.java
+++ b/src/main/java/com/whereyouad/WhereYouAd/domains/user/presentation/docs/UserControllerDocs.java
@@ -127,7 +127,6 @@ public ResponseEntity<DataResponse<UserInfoModifiedResponse>> modifyUserInfo(
             description = "AccessToken 을 헤더로 받아 현재 로그인한 회원을 탈퇴 처리합니다. " +
                     "Soft Delete 방식이며, 30일 유예 기간 이후 스케줄러가 Hard Delete 를 수행합니다.\n\n" +
                     "### 1. 사전 검증 (통과해야 탈퇴 가능)\n" +
-                    "- **광고 플랫폼 연동(PlatformConnection) 존재 여부**: 연동된 광고 플랫폼이 하나라도 남아 있으면 탈퇴가 차단됩니다. 먼저 모든 광고 플랫폼 연동을 해제한 뒤 다시 시도해야 합니다. -> 추후 삭제 API 추가 예정\n\n" +
                     "- **본인이 소유자인 조직에 다른 ACTIVE 멤버 존재**: 본인이 생성자(owner)인 조직에 본인 외 다른 ACTIVE 멤버가 남아 있으면 탈퇴가 차단됩니다. `PATCH /api/org/{orgId}/changeOwner` API 로 소유권을 위임한 뒤 재시도해야 합니다.\n\n" +
                     "### 2. 회원이 속한 워크스페이스(Organization) 처리\n" +
                     "- **단순 ADMIN / MEMBER 로만 속해있는 조직** → 탈퇴 시점에는 별도 처리 없이 유지됩니다. 이후 Hard Delete 단계에서 일괄 삭제됩니다.\n\n" +
@@ -140,13 +139,13 @@ public ResponseEntity<DataResponse<UserInfoModifiedResponse>> modifyUserInfo(
                     "- deletedAt 으로부터 30일 경과한 Soft Deleted 회원이 대상입니다.\n\n" +
                     "- 회원이 owner 인 Soft Deleted 조직과 관련 데이터(워크스페이스 소속 정보 / 활동 타임라인 / AI 인사이트 리포트 / 보낸 초대장 / 조직 로고 S3 이미지) Hard Delete.\n\n" +
                     "- 회원이 속한 모든 워크스페이스에서 회원이 제외됨.\n\n" +
+                    "- 회원이 연동한 모든 광고 플랫폼 연동 정보 Hard Delete + 연관된 광고정보 모두 Hard Delete\n\n" +
                     "- 회원 본인 Hard Delete 후 프로필 이미지 S3 삭제. S3 이미지 삭제 실패는 서버 로그로만 기록됩니다."
     )
     @ApiResponses({
             @ApiResponse(responseCode = "200", description = "성공"),
             @ApiResponse(responseCode = "404_1", description = "USER_404_1 : 해당 사용자 존재하지 않음"),
-            @ApiResponse(responseCode = "400_9", description = "USER_400_9 : 다른 멤버가 속한 조직의 소유자는 탈퇴할 수 없음 (소유권 위임 후 재시도 필요)"),
-            @ApiResponse(responseCode = "400_10", description = "USER_400_10 : 연동된 광고 플랫폼이 존재하여 탈퇴할 수 없음 (모든 연동 해제 후 재시도 필요)")
+            @ApiResponse(responseCode = "400_9", description = "USER_400_9 : 다른 멤버가 속한 조직의 소유자는 탈퇴할 수 없음 (소유권 위임 후 재시도 필요)")
     })
     public ResponseEntity<DataResponse<String>> deleteUser(
             @AuthenticationPrincipal(expression = "userId") Long userId