diff --git a/src/entities/chat/lib/useChatMessages.ts b/src/entities/chat/lib/useChatMessages.ts
index 374c8cd8..12e81b47 100644
--- a/src/entities/chat/lib/useChatMessages.ts
+++ b/src/entities/chat/lib/useChatMessages.ts
@@ -46,6 +46,23 @@ export const useChatMessages = (chatId: number | null) => {
       .flatMap((page) => [...page.messages].reverse());
   }, [data]);
 
+  const lastReadMessageId = useMemo(() => {
+    if (!data || data.pages.length == 0) return null;
+    return data.pages[0].lastReadMessageId;
+  }, [data]);
+
+  const lastOtherMessageId: number | null = useMemo(() => {
+    if (!messages.length) return null;
+
+    for (let i = messages.length - 1; i >= 0; i--) {
+      const msg = messages[i];
+      if (msg.type !== "system" && !msg.isMine) {
+        return msg.messageId;
+      }
+    }
+    return null;
+  }, [messages]);
+
   const pushMessageToCache = (newMsg: MessageProps) => {
     //메시지 리스트 업데이트
     queryClient.setQueryData<InfiniteData<MessagesResponse>>(
@@ -90,6 +107,39 @@ export const useChatMessages = (chatId: number | null) => {
     });
   };
 
+  const applyReadStatus = () => {
+    if (!chatId) return;
+    let stopUpdating = false;
+
+    queryClient.setQueryData<InfiniteData<MessagesResponse>>(
+      ["chatMessages", chatId],
+      (oldData) => {
+        if (!oldData) return oldData;
+
+        const updatedPages = oldData.pages.map((page) => ({
+          ...page,
+          messages: page.messages.map((msg) => {
+            if (stopUpdating) return msg;
+            if (msg.isMine) {
+              if (!msg.isRead) {
+                return { ...msg, isRead: true };
+              } else {
+                stopUpdating = true;
+                return msg;
+              }
+            }
+            return msg;
+          }),
+        }));
+
+        return {
+          pageParams: oldData.pageParams,
+          pages: updatedPages,
+        };
+      },
+    );
+  };
+
   const fetchMoreMessages = async () => {
     const container = scrollContainerRef.current;
     const prevHeight = container?.scrollHeight ?? 0;
@@ -106,7 +156,10 @@ export const useChatMessages = (chatId: number | null) => {
 
   return {
     messages,
+    lastReadMessageId,
+    lastOtherMessageId,
     pushMessageToCache,
+    applyReadStatus,
     fetchMoreMessages,
     hasNextPage,
     isMessagesFirstLoading,
diff --git a/src/entities/chat/lib/useChatSocket.ts b/src/entities/chat/lib/useChatSocket.ts
index 2e6e14b5..f905870a 100644
--- a/src/entities/chat/lib/useChatSocket.ts
+++ b/src/entities/chat/lib/useChatSocket.ts
@@ -1,4 +1,4 @@
-import { useEffect, useRef } from "react";
+import { useState, useEffect, useRef } from "react";
 import { ChatSocket } from "../model/chatSocket";
 import { DealStatus, MessageProps } from "../model/types";
 import { PostStatus } from "@/entities/post/model/types/post";
@@ -6,63 +6,65 @@ import { PostStatus } from "@/entities/post/model/types/post";
 interface QueuedMessage {
   type: "text" | "image";
   content: string;
-  sendAt: string;
 }
 
 export const useChatSocket = (
   chatId: number | null,
+  otherId: number | null,
   pushMessageToCache: (msg: MessageProps) => void,
   scrollToBottom?: () => void,
   onDealUpdate?: (update: {
     postStatus: PostStatus;
     dealStatus: DealStatus;
   }) => void,
+  getLastOtherMessageId?: () => number | null,
+  onMessageRead?: (messageId: number) => void,
 ) => {
+  const [isSocketConnected, setIsSocketConncted] = useState(false);
   const socketRef = useRef<ChatSocket | null>(null);
   const messageQueue = useRef<QueuedMessage[]>([]); // 🔥 메시지 큐
 
   /** 메시지 전송 공통 함수 (push + socket) */
-  const processMessage = (
-    type: "text" | "image",
-    content: string,
-    sendAt: string,
-  ) => {
-    pushMessageToCache({
-      messageId: Date.now(),
-      type,
-      content,
-      isMine: true,
-      sendAt,
-      isRead: true,
-    });
-
+  const processMessage = (type: "text" | "image", content: string) => {
     socketRef.current?.sendMessage(type, content);
-
     requestAnimationFrame(() => scrollToBottom?.());
   };
 
   /** 큐 flush */
   const flushQueue = () => {
     if (!socketRef.current || !socketRef.current.isOpen()) return;
-    messageQueue.current.forEach(({ type, content, sendAt }) => {
-      processMessage(type, content, sendAt);
+    messageQueue.current.forEach(({ type, content }) => {
+      processMessage(type, content);
     });
     messageQueue.current = [];
   };
 
+  //현재 화면 상대 마지막 메시지를 서버에 읽음 처리 요청
+  const readLastMessage = () => {
+    const lastId = getLastOtherMessageId?.();
+    if (lastId && socketRef.current?.isOpen()) {
+      socketRef.current.readMessage(lastId);
+      console.log(`[Socket] Send read_message for ID: ${lastId}`);
+    }
+  };
+
   const connectSocket = async () => {
-    if (!chatId) return;
+    if (!chatId || !otherId) return;
     if (socketRef.current?.isOpen()) return;
 
     if (!socketRef.current) {
-      socketRef.current = new ChatSocket(chatId, {
+      socketRef.current = new ChatSocket(chatId, otherId, {
         onOpen: () => {
+          setIsSocketConncted(true);
           console.log("[Socket] Connected");
           flushQueue();
         },
         onMessage: (msg) => {
           pushMessageToCache(msg);
           requestAnimationFrame(() => scrollToBottom?.());
+          if (!msg.isMine) {
+            readLastMessage();
+          }
         },
         onDealUpdate: (update) => {
           onDealUpdate?.(update);
@@ -76,6 +78,11 @@ export const useChatSocket = (
           });
           requestAnimationFrame(() => scrollToBottom?.());
         },
+        onRead: onMessageRead,
+        onClose: () => {
+          console.log("[Socket] disconnected");
+          setIsSocketConncted(false);
+        },
       });
     }
 
@@ -88,19 +95,18 @@ export const useChatSocket = (
     return () => {
       socketRef.current?.close();
       socketRef.current = null;
+      setIsSocketConncted(false);
     };
   }, [chatId]);
 
   const sendMessage = async (type: "text" | "image", content: string) => {
-    const sendAt = new Date().toISOString();
-
     if (!chatId || !socketRef.current?.isOpen()) {
-      messageQueue.current.push({ type, content, sendAt });
+      messageQueue.current.push({ type, content });
       return;
     }
 
-    processMessage(type, content, sendAt);
+    processMessage(type, content);
   };
 
-  return { sendMessage };
+  return { isSocketConnected, sendMessage, readLastMessage };
 };
diff --git a/src/entities/chat/model/chatSocket.ts b/src/entities/chat/model/chatSocket.ts
index 453bb842..b7db4d2c 100644
--- a/src/entities/chat/model/chatSocket.ts
+++ b/src/entities/chat/model/chatSocket.ts
@@ -10,14 +10,17 @@ export interface ChatSocketEvents extends SocketEvents {
     dealStatus: DealStatus;
     message: string;
   }) => void;
+  onRead?: (messageId: number) => void;
 }
 
 export class ChatSocket extends Socket<ChatSocketEvents> {
   private chatId: number;
+  private otherId: number;
 
-  constructor(chatId: number, events: ChatSocketEvents = {}) {
+  constructor(chatId: number, otherId: number, events: ChatSocketEvents = {}) {
     super(events);
     this.chatId = chatId;
+    this.otherId = otherId;
   }
 
   protected getEndpointPath(): string {
@@ -42,7 +45,13 @@ export class ChatSocket extends Socket<ChatSocketEvents> {
         return;
       }
 
-      if (["welcome", "system", "read"].includes(data.type)) {
+      if (data.type === "read") {
+        console.log(`[Socket] : 읽음 처리 이벤트 수신`);
+        this.events.onRead?.(data.lastReadMessageId);
+        return;
+      }
+
+      if (["welcome", "system"].includes(data.type)) {
         this.events.onSystem?.(data);
         return;
       }
@@ -53,7 +62,7 @@ export class ChatSocket extends Socket<ChatSocketEvents> {
           messageId: data.messageId,
           type: data.type,
           content: data.content,
-          isMine: false,
+          isMine: data.senderId !== this.otherId,
           sendAt: data.createdAt,
           isRead: false,
         };
@@ -73,4 +82,15 @@ export class ChatSocket extends Socket<ChatSocketEvents> {
     const payload = { event: "send_message", type, content };
     this.socket.send(JSON.stringify(payload));
   }
+
+  public readMessage(messageId: number) {
+    if (!this.socket || this.socket.readyState !== WebSocket.OPEN) {
+      console.warn("[ChatSocket] Not connected");
+      return;
+    }
+
+    console.log(`[Socket] : read_message 이벤트 송신 messageId : ${messageId}`);
+    const payload = { event: "read_message", messageId };
+    this.socket.send(JSON.stringify(payload));
+  }
 }
diff --git a/src/entities/chat/model/types.ts b/src/entities/chat/model/types.ts
index 8dacc277..ac30ef4c 100644
--- a/src/entities/chat/model/types.ts
+++ b/src/entities/chat/model/types.ts
@@ -26,4 +26,5 @@ export interface MessagesResponse {
   messages: MessageProps[];
   hasNext: boolean;
   nextCursor: number | null;
+  lastReadMessageId: number;
 }
diff --git a/src/entities/chat/ui/ChattingRoom/ChattingRoom.tsx b/src/entities/chat/ui/ChattingRoom/ChattingRoom.tsx
index b48f0106..2c273180 100644
--- a/src/entities/chat/ui/ChattingRoom/ChattingRoom.tsx
+++ b/src/entities/chat/ui/ChattingRoom/ChattingRoom.tsx
@@ -63,7 +63,10 @@ export const ChattingRoom = ({
 
   const {
     messages,
+    lastReadMessageId,
+    lastOtherMessageId,
     pushMessageToCache,
+    applyReadStatus,
     fetchMoreMessages,
     hasNextPage,
     isError: isChatMessagesError,
@@ -102,13 +105,32 @@ export const ChattingRoom = ({
     }
   }, [messages]);
 
-  const { sendMessage } = useChatSocket(
+  const { isSocketConnected, sendMessage, readLastMessage } = useChatSocket(
     chatId,
+    otherId,
     pushMessageToCache,
     scrollToBottom,
     applyUpdate,
+    () => lastOtherMessageId,
+    applyReadStatus,
   );
 
+  const firstReadRequestDone = useRef(false);
+  useEffect(() => {
+    if (firstReadRequestDone.current) {
+      return;
+    }
+    if (
+      !isMessagesLoading &&
+      isSocketConnected &&
+      messages.length > 0 &&
+      lastOtherMessageId !== null
+    ) {
+      readLastMessage();
+      firstReadRequestDone.current = true;
+    }
+  }, [messages, isSocketConnected]);
+
   const { openModal, closeModal } = useModalStore();
   const [text, setText] = useState("");
   const [image, setImage] = useState<File | null>(null);
diff --git a/src/entities/chat/ui/Message/Message.stories.tsx b/src/entities/chat/ui/Message/Message.stories.tsx
index 4279d110..87d06e5c 100644
--- a/src/entities/chat/ui/Message/Message.stories.tsx
+++ b/src/entities/chat/ui/Message/Message.stories.tsx
@@ -15,6 +15,7 @@ const meta: Meta<typeof Message> = {
     },
     content: { control: "text" },
     isMine: { control: "boolean" },
+    isRead: { contorl: "boolean" },
   },
 };
 
@@ -26,6 +27,7 @@ export const MyText: Story = {
     type: "text",
     content: "네, 아직 있습니다. 상태는 아주 좋아요 🙂",
     isMine: true,
+    isRead: true,
   },
 };
 
@@ -34,6 +36,7 @@ export const OtherText: Story = {
     type: "text",
     content: "안녕하세요! 이 물건 아직 있나요?",
     isMine: false,
+    isRead: false,
   },
 };
 
diff --git a/src/entities/chat/ui/MessageRow/MessageRow.tsx b/src/entities/chat/ui/MessageRow/MessageRow.tsx
index 6e0938e3..a97fc3f9 100644
--- a/src/entities/chat/ui/MessageRow/MessageRow.tsx
+++ b/src/entities/chat/ui/MessageRow/MessageRow.tsx
@@ -46,6 +46,15 @@ export const MessageRow = ({
         )}
 
         <Message {...message} />
+        {message.isMine && !message.isRead && (
+          <span
+            className={`absolute -left-4 text-[11px] font-bold text-blue-400 ${
+              showTime ? "bottom-4" : "bottom-0"
+            }`}
+          >
+            1
+          </span>
+        )}
 
         {showTime && (
           <span