diff --git a/ui/src/components/agents/AgentsHome.tsx b/ui/src/components/agents/AgentsHome.tsx
index 1fd4174a..9e84ef4a 100644
--- a/ui/src/components/agents/AgentsHome.tsx
+++ b/ui/src/components/agents/AgentsHome.tsx
@@ -16,6 +16,10 @@ import {
 } from "@/lib/agents/queries"
 import { useModelOptions } from "@/lib/agents/provider/useModelOptions"
 import { useProfile, useRepos } from "@/lib/profile"
+import {
+  requestNotificationPermission,
+  setNotificationsPref,
+} from "@/lib/notifications"
 
 function promptContent(text: string, images: Array<ImageChunk>) {
   const trimmed = text.trim()
@@ -74,6 +78,9 @@ export function AgentsHome() {
   }, [stream.threadId, queryClient, navigate])
 
   const handleSubmit = (prompt: string, images: Array<ImageChunk>) => {
+    void requestNotificationPermission().then((perm) => {
+      if (perm === "granted") setNotificationsPref(true)
+    })
     draftRef.current = {
       prompt,
       images,
diff --git a/ui/src/lib/agents/useRunCompletionNotifier.ts b/ui/src/lib/agents/useRunCompletionNotifier.ts
new file mode 100644
index 00000000..fcf09653
--- /dev/null
+++ b/ui/src/lib/agents/useRunCompletionNotifier.ts
@@ -0,0 +1,41 @@
+import { useEffect, useRef } from "react"
+
+import type { AgentThread } from "@/lib/agents/types"
+import { showRunNotification } from "@/lib/notifications"
+
+const TERMINAL_STATUSES = new Set(["finished", "error", "interrupted"])
+
+/**
+ * Watches the thread list for transitions from `running` to a terminal status
+ * and fires a browser notification for each run that completes. Suppresses
+ * notifications for the thread the user is currently viewing only when the
+ * page is visible — background tabs still notify even for the active thread.
+ */
+export function useRunCompletionNotifier(
+  threads: Array<AgentThread> | undefined,
+  activeThreadId?: string
+) {
+  const prevStatusRef = useRef<Map<string, string>>(new Map())
+
+  useEffect(() => {
+    if (!threads) return
+    const isViewingThread =
+      !!activeThreadId && document.visibilityState === "visible"
+    const prev = prevStatusRef.current
+    for (const thread of threads) {
+      const prevStatus = prev.get(thread.id)
+      if (prevStatus === undefined) {
+        prev.set(thread.id, thread.status)
+        continue
+      }
+      if (
+        prevStatus === "running" &&
+        TERMINAL_STATUSES.has(thread.status) &&
+        !(isViewingThread && thread.id === activeThreadId)
+      ) {
+        showRunNotification(thread)
+      }
+      prev.set(thread.id, thread.status)
+    }
+  }, [threads, activeThreadId])
+}
diff --git a/ui/src/lib/notifications.ts b/ui/src/lib/notifications.ts
new file mode 100644
index 00000000..20edaaae
--- /dev/null
+++ b/ui/src/lib/notifications.ts
@@ -0,0 +1,62 @@
+import type { AgentThread } from "./agents/types"
+
+export const NOTIFICATIONS_PREF_KEY = "open-swe-notifications-enabled"
+
+export function notificationsSupported(): boolean {
+  return typeof window !== "undefined" && "Notification" in window
+}
+
+export function getNotificationPermission(): NotificationPermission | null {
+  if (!notificationsSupported()) return null
+  return Notification.permission
+}
+
+export function notificationsEnabled(): boolean {
+  if (!notificationsSupported()) return false
+  if (Notification.permission !== "granted") return false
+  try {
+    return localStorage.getItem(NOTIFICATIONS_PREF_KEY) === "true"
+  } catch {
+    return false
+  }
+}
+
+export async function requestNotificationPermission(): Promise<NotificationPermission | null> {
+  if (!notificationsSupported()) return null
+  if (Notification.permission === "granted") return "granted"
+  if (Notification.permission === "denied") return "denied"
+  return Notification.requestPermission()
+}
+
+export function setNotificationsPref(enabled: boolean) {
+  try {
+    localStorage.setItem(NOTIFICATIONS_PREF_KEY, String(enabled))
+  } catch {
+    /* ignore */
+  }
+}
+
+export function showRunNotification(thread: AgentThread) {
+  if (!notificationsEnabled()) return
+  const statusLabel =
+    thread.status === "error"
+      ? "encountered an error"
+      : thread.status === "interrupted"
+        ? "was interrupted"
+        : "finished"
+  const title = thread.title || "Agent run"
+  const body = `Run ${statusLabel}.`
+  try {
+    const n = new Notification(title, {
+      body,
+      icon: "/logo-mark.png",
+      tag: `run-${thread.id}`,
+    })
+    n.onclick = () => {
+      window.focus()
+      n.close()
+    }
+  } catch {
+    /* ignore */
+  }
+}
diff --git a/ui/src/routes/agents.tsx b/ui/src/routes/agents.tsx
index e93d3433..1f3e79d5 100644
--- a/ui/src/routes/agents.tsx
+++ b/ui/src/routes/agents.tsx
@@ -9,6 +9,8 @@ import { AgentsShell } from "@/components/agents/AgentsSidebar"
 import { Skeleton } from "@/components/ui/skeleton"
 import agentsCss from "@/styles/agents.css?url"
 import { AgentThreadStreamProvider } from "@/lib/agents/AgentThreadStreamProvider"
+import { useAgentThreads } from "@/lib/agents/queries"
+import { useRunCompletionNotifier } from "@/lib/agents/useRunCompletionNotifier"
 import { useSession } from "@/lib/session"
 
 export const Route = createFileRoute("/agents")({
@@ -33,6 +35,9 @@ function AgentsLayout() {
       ? threadId
       : undefined
 
+  const threadsQuery = useAgentThreads()
+  useRunCompletionNotifier(threadsQuery.data, activeThreadId)
+
   if (session.isLoading) {
     return (
       <main className="agents-ui flex h-svh items-center justify-center bg-[var(--ui-bg)] p-6">
diff --git a/ui/src/routes/my-settings.tsx b/ui/src/routes/my-settings.tsx
index 1c1e002e..1367bded 100644
--- a/ui/src/routes/my-settings.tsx
+++ b/ui/src/routes/my-settings.tsx
@@ -14,6 +14,7 @@ import {
   SelectValue,
 } from "@/components/ui/select"
 import { Skeleton } from "@/components/ui/skeleton"
+import { Switch } from "@/components/ui/switch"
 import { api, slackConnectUrl } from "@/lib/api"
 import {
   buildProfileUpdate,
@@ -22,6 +23,12 @@ import {
   useSaveProfile,
 } from "@/lib/profile"
 import { useSession } from "@/lib/session"
+import {
+  notificationsEnabled,
+  notificationsSupported,
+  requestNotificationPermission,
+  setNotificationsPref,
+} from "@/lib/notifications"
 import { cn } from "@/lib/utils"
 
 export const Route = createFileRoute("/my-settings")({
@@ -118,6 +125,68 @@ function UserMappingSection({ session }: { session: SessionUser }) {
   )
 }
 
+function NotificationsSection() {
+  const supported = notificationsSupported()
+  const [enabled, setEnabled] = useState(() => notificationsEnabled())
+  const [permissionDenied, setPermissionDenied] = useState(
+    () => supported && Notification.permission === "denied"
+  )
+
+  const handleToggle = async (checked: boolean) => {
+    if (checked) {
+      const perm = await requestNotificationPermission()
+      if (perm === "granted") {
+        setNotificationsPref(true)
+        setEnabled(true)
+      } else if (perm === "denied") {
+        setPermissionDenied(true)
+      }
+    } else {
+      setNotificationsPref(false)
+      setEnabled(false)
+    }
+  }
+
+  if (!supported) {
+    return (
+      <SettingsSection title="Notifications">
+        <SettingsRow
+          label="Desktop notifications"
+          description="Your browser does not support desktop notifications."
+          control={
+            <span className="text-[10px] text-muted-foreground">
+              Not supported
+            </span>
+          }
+        />
+      </SettingsSection>
+    )
+  }
+
+  return (
+    <SettingsSection
+      title="Notifications"
+      description="Get a desktop notification when an agent run finishes."
+    >
+      <SettingsRow
+        label="Desktop notifications"
+        description={
+          permissionDenied
+            ? "Permission was denied. Re-enable it in your browser's site settings."
+            : "Show a notification when a run completes."
+        }
+        control={
+          <Switch
+            checked={enabled}
+            onCheckedChange={handleToggle}
+            disabled={permissionDenied}
+          />
+        }
+      />
+    </SettingsSection>
+  )
+}
+
 function MySettingsPage() {
   const session = useSession()
   const qc = useQueryClient()
@@ -216,6 +285,8 @@ function MySettingsPage() {
         />
       </SettingsSection>
 
+      <NotificationsSection />
+
       <SettingsSection title="Account">
         <SettingsRow
           label="Sign out"