diff --git a/src/hqt/tui/app.py b/src/hqt/tui/app.py
index 4df8d0b..dd2031d 100644
--- a/src/hqt/tui/app.py
+++ b/src/hqt/tui/app.py
@@ -72,6 +72,7 @@ class HqtApp(App):
         Binding("tab", "toggle_focus", "Switch Panel"),
         Binding("h", "focus_projects", "Projects"),
         Binding("l", "focus_sessions", "Sessions"),
+        Binding("x", "archive_session", "Archive"),
         Binding("d", "delete_session", "Delete Session"),
         Binding("enter", "attach_session", "Attach", priority=True),
         Binding("r", "rename_session", "Rename"),
@@ -436,6 +437,17 @@ class HqtApp(App):
 
             self._run_service_worker(_do())
 
+    def action_archive_session(self) -> None:
+        sid = self.query_one(SessionList).get_selected_session_id()
+        if not sid:
+            return
+
+        async def _do() -> None:
+            await self._sessions().archive_session(sid)
+            await self._refresh_sessions()
+
+        self._run_service_worker(_do())
+
     def action_schedule_prompt(self) -> None:
         sid = self.query_one(SessionList).get_selected_session_id()
         if sid is None:
diff --git a/tests/test_tui.py b/tests/test_tui.py
index b9bcf94..1afce4e 100644
--- a/tests/test_tui.py
+++ b/tests/test_tui.py
@@ -2035,3 +2035,56 @@ async def test_session_list_header_reflects_archived_mode():
         sl.set_mode(archived=False)
         await pilot.pause()
         assert str(header.render()) == "Sessions"
+
+
+@pytest.mark.asyncio
+async def test_archive_session_binding_exists():
+    bindings = {b.key: b for b in HqtApp.BINDINGS}
+    assert bindings["x"].action == "archive_session"
+
+
+@pytest.mark.asyncio
+async def test_archive_session_action_calls_service_and_refreshes():
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        from hqt.db.models import Project, Harness, Session
+        from hqt.tui.widgets.session_list import SessionList
+
+        seed_db = app._db_factory()
+        proj = Project(name="arch-proj", path="/tmp/arch-proj")
+        seed_db.add(proj)
+        seed_db.flush()
+        harness = seed_db.query(Harness).first()
+        sess = Session(
+            project_id=proj.id,
+            harness_id=harness.id,
+            tmux_session_name="hqt-arch-action",
+            archived=False,
+        )
+        seed_db.add(sess)
+        seed_db.commit()
+        proj_id = proj.id
+        sess_id = sess.id
+        seed_db.close()
+
+        app._selected_project_id = proj_id
+        await app._refresh_sessions()
+        await pilot.pause()
+
+        sl = app.query_one(SessionList)
+        sl.query_one("#session-list").focus()
+        await pilot.press("down")
+        await pilot.pause()
+        assert sl.get_selected_session_id() == sess_id
+
+        mock_service = MagicMock()
+        mock_service.archive_session = AsyncMock()
+        mock_service.list_sessions = AsyncMock(return_value=[])
+        mock_service.sync_window_labels = AsyncMock(return_value=[])
+        app._session_service = mock_service
+
+        await app.run_action("archive_session")
+        await pilot.pause()
+
+        mock_service.archive_session.assert_awaited_once_with(sess_id)
+        mock_service.list_sessions.assert_awaited()