diff --git a/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/ChatRepository.kt b/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/ChatRepository.kt
index 112d198c..ea07006b 100644
--- a/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/ChatRepository.kt
+++ b/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/ChatRepository.kt
@@ -210,4 +210,13 @@ class ChatRepository(
             .subscribeOn(Schedulers.io())
             .map { ensureSuccess(it) }
     }
+
+    /**
+     * 방별 로컬 메시지 전체 삭제
+     */
+    fun clearMessagesByRoom(roomId: Long): Completable {
+        return Completable.fromAction {
+            kotlinx.coroutines.runBlocking { chatDao.deleteMessagesByRoomId(roomId) }
+        }.subscribeOn(Schedulers.io())
+    }
 }
diff --git a/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/ChatRoomActivity.kt b/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/ChatRoomActivity.kt
index ce322dca..49a93967 100644
--- a/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/ChatRoomActivity.kt
+++ b/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/ChatRoomActivity.kt
@@ -884,6 +884,18 @@ class ChatRoomActivity : BaseActivity<ActivityChatRoomBinding>(
         return if (id > 0) id else null
     }
 
+    private fun clearLocalPrefsForRoom(roomId: Long) {
+        val keys = listOf(
+            "chat_bg_visible_room_$roomId",
+            "chat_bg_url_room_$roomId",
+            "chat_bg_image_id_room_$roomId",
+            noticePrefKey(roomId)
+        )
+        prefs.edit {
+            keys.forEach { remove(it) }
+        }
+    }
+
     fun onResetChatRequested() {
         val title = "대화 초기화"
         val desc = "지금까지의 대화가 모두 초기화 되고 새롭게 대화를 시작합니다."
@@ -896,6 +908,12 @@ class ChatRoomActivity : BaseActivity<ActivityChatRoomBinding>(
             confirmButtonClick = {
                 val token = "Bearer ${SharedPreferenceManager.token}"
                 val disposable = chatRepository.resetChatRoom(token = token, roomId = roomId)
+                    .flatMap { response ->
+                        // 로컬 데이터(이 방) 삭제: Prefs + DB
+                        clearLocalPrefsForRoom(roomId)
+                        chatRepository.clearMessagesByRoom(roomId)
+                            .andThen(io.reactivex.rxjava3.core.Single.just(response))
+                    }
                     .observeOn(AndroidSchedulers.mainThread())
                     .subscribe({ response ->
                         val intent = newIntent(this, response.chatRoomId)
diff --git a/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/db/ChatMessageDao.kt b/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/db/ChatMessageDao.kt
index 19d3efbd..0241b51a 100644
--- a/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/db/ChatMessageDao.kt
+++ b/app/src/main/java/kr/co/vividnext/sodalive/chat/talk/room/db/ChatMessageDao.kt
@@ -37,4 +37,7 @@ interface ChatMessageDao {
 
     @Query("SELECT DISTINCT roomId FROM chat_messages")
     suspend fun getAllRoomIds(): List<Long>
+
+    @Query("DELETE FROM chat_messages WHERE roomId = :roomId")
+    suspend fun deleteMessagesByRoomId(roomId: Long)
 }