diff --git a/mobile/app/index.tsx b/mobile/app/index.tsx
index 2279aec..75a55e8 100644
--- a/mobile/app/index.tsx
+++ b/mobile/app/index.tsx
@@ -15,6 +15,7 @@ import { SettingsModal } from '../components/SettingsModal';
 import { ConfirmModal, type ConfirmOption } from '../components/ConfirmModal';
 import { UploadModal } from '../components/UploadModal';
 import { SyncStatusIcon } from '../components/SyncStatusIcon';
+import { NetworkStatusBar } from '../components/NetworkStatusBar';
 import { useSyncQueue } from '../hooks/useSyncQueue';
 import { useUploadQueue } from '../hooks/useUploadQueue';
 import { useAutoSync } from '../hooks/useAutoSync';
@@ -161,6 +162,7 @@ export function HomeScreen() {
     navigation.setOptions({
       headerRight: () => (
         <View style={{ flexDirection: 'row', alignItems: 'center' }}>
+          <NetworkStatusBar />
           <SyncStatusIcon
             isSyncing={isSyncing}
             pendingCount={pendingCount}
diff --git a/mobile/components/NetworkStatusBar.tsx b/mobile/components/NetworkStatusBar.tsx
new file mode 100644
index 0000000..fd3561b
--- /dev/null
+++ b/mobile/components/NetworkStatusBar.tsx
@@ -0,0 +1,54 @@
+import React from 'react';
+import { View, Text, StyleSheet } from 'react-native';
+import { MaterialIcons } from '@expo/vector-icons';
+import { useNetworkStatus } from '../hooks/useNetworkStatus';
+
+export function NetworkStatusBar() {
+  const { isOnline } = useNetworkStatus();
+
+  if (isOnline) {
+    return (
+      <View style={styles.container}>
+        <View style={styles.dotOnline} />
+      </View>
+    );
+  }
+
+  return (
+    <View style={styles.container}>
+      <View style={styles.offlineBadge}>
+        <MaterialIcons name="cloud-off" size={14} color="#fff" />
+        <Text style={styles.offlineText}>Offline</Text>
+      </View>
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    marginRight: 4,
+    padding: 4,
+    alignItems: 'center',
+    justifyContent: 'center',
+  },
+  dotOnline: {
+    width: 8,
+    height: 8,
+    borderRadius: 4,
+    backgroundColor: '#4CAF50',
+  },
+  offlineBadge: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    backgroundColor: '#E53935',
+    borderRadius: 12,
+    paddingHorizontal: 8,
+    paddingVertical: 4,
+    gap: 4,
+  },
+  offlineText: {
+    fontSize: 11,
+    fontWeight: '700',
+    color: '#fff',
+  },
+});
diff --git a/mobile/hooks/useNetworkStatus.ts b/mobile/hooks/useNetworkStatus.ts
new file mode 100644
index 0000000..9a23b65
--- /dev/null
+++ b/mobile/hooks/useNetworkStatus.ts
@@ -0,0 +1,55 @@
+import { useSyncExternalStore, useRef } from 'react';
+import NetInfo, { NetInfoState, NetInfoSubscription } from '@react-native-community/netinfo';
+
+type Listener = () => void;
+
+let state: NetInfoState | null = null;
+const listeners = new Set<Listener>();
+let subscription: NetInfoSubscription | null = null;
+
+function subscribe(listener: Listener): () => void {
+  listeners.add(listener);
+  return () => { listeners.delete(listener); };
+}
+
+function getSnapshot(): boolean {
+  return state?.isConnected ?? true;
+}
+
+function initIfNeeded() {
+  if (subscription) return;
+  NetInfo.fetch().then((info) => {
+    state = info;
+    listeners.forEach((l) => l());
+  });
+  subscription = NetInfo.addEventListener((info) => {
+    state = info;
+    listeners.forEach((l) => l());
+  });
+}
+
+export interface NetworkStatus {
+  isOnline: boolean;
+  isWifi: boolean;
+  isCellular: boolean;
+  connectionType: string;
+  isInternetReachable: boolean | null;
+}
+
+export function useNetworkStatus(): NetworkStatus {
+  const mountRef = useRef(false);
+  if (!mountRef.current) {
+    initIfNeeded();
+    mountRef.current = true;
+  }
+
+  const isConnected = useSyncExternalStore(subscribe, getSnapshot);
+
+  return {
+    isOnline: isConnected,
+    isWifi: state?.type === 'wifi',
+    isCellular: state?.type === 'cellular',
+    connectionType: state?.type ?? 'unknown',
+    isInternetReachable: state?.isInternetReachable ?? null,
+  };
+}