diff --git a/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaEntity.java b/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaEntity.java
index 7aa31493e..611e214a2 100644
--- a/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaEntity.java
+++ b/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaEntity.java
@@ -61,7 +61,7 @@ public class GroupJpaEntity {
     @Enumerated(EnumType.STRING)
     private GroupCategory category;
 
-    @ManyToOne(fetch = FetchType.LAZY, optional = false)
-    @JoinColumn(name = "fk_user_id", nullable = false)
+    @ManyToOne(fetch = FetchType.LAZY, optional = true)
+    @JoinColumn(name = "fk_user_id", nullable = true)
     private UserJpaEntity owner;
 }
diff --git a/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaMapper.java b/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaMapper.java
index f4d63aa8b..8f725f931 100644
--- a/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaMapper.java
+++ b/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaMapper.java
@@ -38,7 +38,7 @@ public Group toDomain(GroupJpaEntity groupJpaEntity) {
                 groupJpaEntity.getPassword(),
                 groupJpaEntity.getPasswordRequired(),
                 groupJpaEntity.getCategory(),
-                groupJpaEntity.getOwner().getId()
+                groupJpaEntity.getOwner() != null ? groupJpaEntity.getOwner().getId() : null
         );
     }
 }
diff --git a/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaRepository.java b/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaRepository.java
index 4937fa0ff..8ea4676f8 100644
--- a/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaRepository.java
+++ b/src/main/java/com/process/clash/adapter/persistence/group/GroupJpaRepository.java
@@ -14,7 +14,8 @@
 public interface GroupJpaRepository extends JpaRepository<GroupJpaEntity, Long> {
 
     @EntityGraph(attributePaths = {"owner"})
-    Page<GroupJpaEntity> findAll(Pageable pageable);
+    @Query("select g from GroupJpaEntity g where g.category != :excluded")
+    Page<GroupJpaEntity> findAllExcluding(@Param("excluded") GroupCategory excluded, Pageable pageable);
 
     @EntityGraph(attributePaths = {"owner"})
     Page<GroupJpaEntity> findAllByCategory(GroupCategory category, Pageable pageable);
@@ -22,6 +23,9 @@ public interface GroupJpaRepository extends JpaRepository<GroupJpaEntity, Long>
     @EntityGraph(attributePaths = {"owner"})
     Optional<GroupJpaEntity> findById(Long id);
 
+    @EntityGraph(attributePaths = {"owner"})
+    Optional<GroupJpaEntity> findByCategory(GroupCategory category);
+
     boolean existsByName(String name);
 
     @EntityGraph(attributePaths = {"owner"})
@@ -30,8 +34,9 @@ public interface GroupJpaRepository extends JpaRepository<GroupJpaEntity, Long>
         from GroupJpaEntity g
         join GroupMemberJpaEntity gm on gm.group = g
         where gm.user.id = :userId
+        and g.category != :excluded
     """)
-    Page<GroupJpaEntity> findAllByMemberUserId(@Param("userId") Long userId, Pageable pageable);
+    Page<GroupJpaEntity> findAllByMemberUserId(@Param("userId") Long userId, @Param("excluded") GroupCategory excluded, Pageable pageable);
 
     @EntityGraph(attributePaths = {"owner"})
     @Query("""
diff --git a/src/main/java/com/process/clash/adapter/persistence/group/GroupPersistenceAdapter.java b/src/main/java/com/process/clash/adapter/persistence/group/GroupPersistenceAdapter.java
index 30b1a01cb..ab90a7ca0 100644
--- a/src/main/java/com/process/clash/adapter/persistence/group/GroupPersistenceAdapter.java
+++ b/src/main/java/com/process/clash/adapter/persistence/group/GroupPersistenceAdapter.java
@@ -31,12 +31,19 @@ public class GroupPersistenceAdapter implements GroupRepositoryPort {
 
     @Override
     public Group save(Group group) {
-        UserJpaEntity owner = userJpaRepository.getReferenceById(group.ownerId());
+        UserJpaEntity owner = group.ownerId() != null
+            ? userJpaRepository.getReferenceById(group.ownerId())
+            : null;
         GroupJpaEntity entity = groupJpaMapper.toJpaEntity(group, owner);
         GroupJpaEntity saved = groupJpaRepository.save(entity);
         return groupJpaMapper.toDomain(saved);
     }
 
+    @Override
+    public Optional<Group> findByCategory(GroupCategory category) {
+        return groupJpaRepository.findByCategory(category).map(groupJpaMapper::toDomain);
+    }
+
     @Override
     public Optional<Group> findById(Long groupId) {
         return groupJpaRepository.findById(groupId)
@@ -52,7 +59,7 @@ public void deleteById(Long groupId) {
     @Override
     public PageResult findAllByPage(Integer page, Integer size) {
         Pageable pageable = PageRequest.of(page - 1, size, Sort.by(Sort.Direction.DESC, "createdAt"));
-        Page<GroupJpaEntity> pageResult = groupJpaRepository.findAll(pageable);
+        Page<GroupJpaEntity> pageResult = groupJpaRepository.findAllExcluding(GroupCategory.GLOBAL, pageable);
         return mapPageResult(pageResult);
     }
 
@@ -66,12 +73,15 @@ public PageResult findAllByPageAndCategory(Integer page, Integer size, GroupCate
     @Override
     public PageResult findAllByMemberUserId(Long userId, Integer page, Integer size) {
         Pageable pageable = PageRequest.of(page - 1, size, Sort.by(Sort.Direction.DESC, "createdAt"));
-        Page<GroupJpaEntity> pageResult = groupJpaRepository.findAllByMemberUserId(userId, pageable);
+        Page<GroupJpaEntity> pageResult = groupJpaRepository.findAllByMemberUserId(userId, GroupCategory.GLOBAL, pageable);
         return mapPageResult(pageResult);
     }
 
     @Override
     public PageResult findAllByMemberUserIdAndCategory(Long userId, Integer page, Integer size, GroupCategory category) {
+        if (category == GroupCategory.GLOBAL) {
+            return new PageResult(List.of(), 0);
+        }
         Pageable pageable = PageRequest.of(page - 1, size, Sort.by(Sort.Direction.DESC, "createdAt"));
         Page<GroupJpaEntity> pageResult = groupJpaRepository.findAllByMemberUserIdAndCategory(userId, category, pageable);
         return mapPageResult(pageResult);
diff --git a/src/main/java/com/process/clash/adapter/web/group/util/GroupCategoryConverter.java b/src/main/java/com/process/clash/adapter/web/group/util/GroupCategoryConverter.java
index b864e6cb0..61006def2 100644
--- a/src/main/java/com/process/clash/adapter/web/group/util/GroupCategoryConverter.java
+++ b/src/main/java/com/process/clash/adapter/web/group/util/GroupCategoryConverter.java
@@ -25,6 +25,10 @@ public static GroupCategory toCategoryFilter(String category) {
             return null;
         }
 
+        if ("GLOBAL".equalsIgnoreCase(category)) {
+            throw new InvalidCategoryException("유효하지 않은 카테고리입니다: 'GLOBAL'");
+        }
+
         try {
             return GroupCategory.valueOf(category.toUpperCase(Locale.ROOT));
         } catch (IllegalArgumentException e) {
diff --git a/src/main/java/com/process/clash/application/group/exception/exception/conflict/CannotQuitGlobalGroupException.java b/src/main/java/com/process/clash/application/group/exception/exception/conflict/CannotQuitGlobalGroupException.java
new file mode 100644
index 000000000..1c07b5762
--- /dev/null
+++ b/src/main/java/com/process/clash/application/group/exception/exception/conflict/CannotQuitGlobalGroupException.java
@@ -0,0 +1,10 @@
+package com.process.clash.application.group.exception.exception.conflict;
+
+import com.process.clash.application.common.exception.exception.ConflictException;
+import com.process.clash.application.group.exception.statuscode.GroupStatusCode;
+
+public class CannotQuitGlobalGroupException extends ConflictException {
+    public CannotQuitGlobalGroupException() {
+        super(GroupStatusCode.CANNOT_QUIT_GLOBAL_GROUP);
+    }
+}
diff --git a/src/main/java/com/process/clash/application/group/exception/statuscode/GroupStatusCode.java b/src/main/java/com/process/clash/application/group/exception/statuscode/GroupStatusCode.java
index cdc324027..c452c9e80 100644
--- a/src/main/java/com/process/clash/application/group/exception/statuscode/GroupStatusCode.java
+++ b/src/main/java/com/process/clash/application/group/exception/statuscode/GroupStatusCode.java
@@ -67,6 +67,12 @@ public enum GroupStatusCode implements StatusCode {
         "DUPLICATE_GROUP_NAME",
         "이미 사용 중인 그룹 이름입니다.",
         HttpStatus.CONFLICT
+    ),
+
+    CANNOT_QUIT_GLOBAL_GROUP(
+        "CANNOT_QUIT_GLOBAL_GROUP",
+        "전체 유저 그룹에서는 탈퇴할 수 없습니다.",
+        HttpStatus.CONFLICT
     );
 
     private final String code;
diff --git a/src/main/java/com/process/clash/application/group/policy/GroupPolicy.java b/src/main/java/com/process/clash/application/group/policy/GroupPolicy.java
index 000416d2e..94e623283 100644
--- a/src/main/java/com/process/clash/application/group/policy/GroupPolicy.java
+++ b/src/main/java/com/process/clash/application/group/policy/GroupPolicy.java
@@ -2,11 +2,13 @@
 
 import com.process.clash.application.common.actor.Actor;
 import com.process.clash.application.common.exception.exception.ValidationException;
+import com.process.clash.application.group.exception.exception.conflict.CannotQuitGlobalGroupException;
 import com.process.clash.application.group.exception.exception.conflict.GroupDuplicateNameException;
 import com.process.clash.application.group.exception.exception.conflict.GroupMemberLimitReachedException;
 import com.process.clash.application.group.exception.exception.conflict.GroupOwnerCannotQuitException;
 import com.process.clash.application.group.exception.exception.forbidden.GroupAccessDeniedException;
 import com.process.clash.domain.group.entity.Group;
+import com.process.clash.domain.group.enums.GroupCategory;
 import org.springframework.stereotype.Component;
 
 @Component
@@ -43,8 +45,23 @@ public void validateMemberLimit(int maxMembers, int memberCount) {
     }
 
     public void canQuitGroup(Actor actor, Group group) {
+        if (group.category() == GroupCategory.GLOBAL) {
+            throw new CannotQuitGlobalGroupException();
+        }
         if (group.ownerId().equals(actor.id())) {
             throw new GroupOwnerCannotQuitException();
         }
     }
+
+    public void validateNotGlobal(Group group) {
+        if (group.category() == GroupCategory.GLOBAL) {
+            throw new GroupAccessDeniedException();
+        }
+    }
+
+    public void validateNotGlobal(GroupCategory category) {
+        if (category == GroupCategory.GLOBAL) {
+            throw new GroupAccessDeniedException();
+        }
+    }
 }
diff --git a/src/main/java/com/process/clash/application/group/port/out/GroupRepositoryPort.java b/src/main/java/com/process/clash/application/group/port/out/GroupRepositoryPort.java
index 85c7ec2de..7e817dcca 100644
--- a/src/main/java/com/process/clash/application/group/port/out/GroupRepositoryPort.java
+++ b/src/main/java/com/process/clash/application/group/port/out/GroupRepositoryPort.java
@@ -13,6 +13,8 @@ public interface GroupRepositoryPort {
 
     Optional<Group> findById(Long groupId);
 
+    Optional<Group> findByCategory(GroupCategory category);
+
     void deleteById(Long groupId);
 
     PageResult findAllByPage(Integer page, Integer size);
diff --git a/src/main/java/com/process/clash/application/group/service/DeleteGroupService.java b/src/main/java/com/process/clash/application/group/service/DeleteGroupService.java
index 590809003..999d00bcc 100644
--- a/src/main/java/com/process/clash/application/group/service/DeleteGroupService.java
+++ b/src/main/java/com/process/clash/application/group/service/DeleteGroupService.java
@@ -26,6 +26,7 @@ public void execute(DeleteGroupData.Command command) {
         Group group = groupRepositoryPort.findById(command.groupId())
             .orElseThrow(GroupNotFoundException::new);
 
+        groupPolicy.validateNotGlobal(group);
         groupPolicy.validateOwnership(command.actor(), group);
         List<Long> memberUserIds = groupRepositoryPort.findMemberUserIdsByGroupIds(List.of(group.id()));
         groupRepositoryPort.deleteById(group.id());
diff --git a/src/main/java/com/process/clash/application/group/service/UpdateGroupService.java b/src/main/java/com/process/clash/application/group/service/UpdateGroupService.java
index 57451bbcf..552207b73 100644
--- a/src/main/java/com/process/clash/application/group/service/UpdateGroupService.java
+++ b/src/main/java/com/process/clash/application/group/service/UpdateGroupService.java
@@ -30,6 +30,8 @@ public void execute(UpdateGroupData.Command command) {
             .orElseThrow(GroupNotFoundException::new);
 
         int currentMemberCount = groupRepositoryPort.countMembers(command.groupId());
+        policy.validateNotGlobal(group);
+        policy.validateNotGlobal(command.category());
         policy.validateOwnership(command.actor(), group);
         policy.validateMaxMembers(command.maxMembers());
         policy.validateMemberLimit(group.maxMembers(), currentMemberCount);
diff --git a/src/main/java/com/process/clash/application/user/user/service/VerifyEmailService.java b/src/main/java/com/process/clash/application/user/user/service/VerifyEmailService.java
index 13b0ec934..42ff91eb2 100644
--- a/src/main/java/com/process/clash/application/user/user/service/VerifyEmailService.java
+++ b/src/main/java/com/process/clash/application/user/user/service/VerifyEmailService.java
@@ -1,5 +1,6 @@
 package com.process.clash.application.user.user.service;
 
+import com.process.clash.application.group.port.out.GroupRepositoryPort;
 import com.process.clash.application.mail.port.out.VerificationCodePort;
 import com.process.clash.application.user.user.data.VerifyEmailData;
 import com.process.clash.application.user.user.exception.exception.badrequest.VerificationCodeExpiredOrWrongEmailException;
@@ -10,6 +11,7 @@
 import com.process.clash.application.user.user.port.in.VerifyEmailUseCase;
 import com.process.clash.application.user.user.port.out.PendingUserCachePort;
 import com.process.clash.application.user.user.port.out.UserRepositoryPort;
+import com.process.clash.domain.group.enums.GroupCategory;
 import com.process.clash.domain.user.user.entity.User;
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
@@ -22,6 +24,7 @@ public class VerifyEmailService implements VerifyEmailUseCase {
     private final VerificationCodePort verificationCodePort;
     private final UserRepositoryPort userRepositoryPort;
     private final PendingUserCachePort pendingUserCachePort;
+    private final GroupRepositoryPort groupRepositoryPort;
 
     @Override
     @Transactional
@@ -46,7 +49,11 @@ public void execute(VerifyEmailData.Command command) {
         }
 
         // 인증 완료 처리 후 DB 저장
-        userRepositoryPort.save(pendingUser.active());
+        User savedUser = userRepositoryPort.save(pendingUser.active());
+
+        // 전체 유저 그룹 자동 가입
+        groupRepositoryPort.findByCategory(GroupCategory.GLOBAL)
+            .ifPresent(g -> groupRepositoryPort.addMember(g.id(), savedUser.id()));
 
         // Redis 정리
         pendingUserCachePort.delete(command.token());
diff --git a/src/main/java/com/process/clash/domain/group/enums/GroupCategory.java b/src/main/java/com/process/clash/domain/group/enums/GroupCategory.java
index 1283491cd..387aa7d7f 100644
--- a/src/main/java/com/process/clash/domain/group/enums/GroupCategory.java
+++ b/src/main/java/com/process/clash/domain/group/enums/GroupCategory.java
@@ -5,5 +5,6 @@ public enum GroupCategory {
     CLUB,
     TEAM,
     NARSHA,
-    ETC
+    ETC,
+    GLOBAL
 }
diff --git a/src/main/resources/db/migration/V42__add_global_user_group.sql b/src/main/resources/db/migration/V42__add_global_user_group.sql
new file mode 100644
index 000000000..de823482e
--- /dev/null
+++ b/src/main/resources/db/migration/V42__add_global_user_group.sql
@@ -0,0 +1,12 @@
+-- 1. groups 테이블의 fk_user_id 컬럼을 nullable로 변경
+ALTER TABLE groups ALTER COLUMN fk_user_id DROP NOT NULL;
+
+-- 2. 전체 유저 그룹 생성 (owner 없음)
+INSERT INTO groups (created_at, updated_at, name, description, max_members, password, password_required, category, fk_user_id)
+VALUES (NOW(), NOW(), '전체 유저', '모든 클래시 유저가 자동으로 참여하는 그룹입니다.', 2147483647, '', false, 'GLOBAL', NULL);
+
+-- 3. 기존 활성 유저 전원을 GLOBAL 그룹에 추가
+INSERT INTO group_members (fk_group_id, fk_user_id)
+SELECT (SELECT id FROM groups WHERE category = 'GLOBAL'), u.id
+FROM users u
+WHERE u.user_status = 'ACTIVE';