diff --git a/src/pages/agent-office/components/ActivityTimeline.jsx b/src/pages/agent-office/components/ActivityTimeline.jsx
new file mode 100644
index 0000000..1ebd1db
--- /dev/null
+++ b/src/pages/agent-office/components/ActivityTimeline.jsx
@@ -0,0 +1,53 @@
+// src/pages/agent-office/components/ActivityTimeline.jsx
+import { useState, useRef, useEffect } from 'react';
+import { useActivityFeed } from '../hooks/useActivityFeed.js';
+import ActivityFilters from './ActivityFilters.jsx';
+import ActivityItem from './ActivityItem.jsx';
+
+const DEFAULT_FILTERS = { agent_id: '', type: '', status: '', days: 7 };
+
+export default function ActivityTimeline({ refreshTrigger, onSelectAgent }) {
+  const [filters, setFilters] = useState(DEFAULT_FILTERS);
+  const { items, total, loading, error, hasMore, loadMore, retry } = useActivityFeed(filters, refreshTrigger);
+
+  const sentinelRef = useRef(null);
+  useEffect(() => {
+    const el = sentinelRef.current;
+    if (!el) return;
+    const io = new IntersectionObserver(entries => {
+      if (entries[0].isIntersecting) loadMore();
+    }, { rootMargin: '120px' });
+    io.observe(el);
+    return () => io.disconnect();
+  }, [loadMore, items.length]);
+
+  return (
+    <div className="ao-sidepanel ao-activity">
+      <div className="ao-sidepanel-header ao-activity-header">
+        <div className="ao-sidepanel-name">팀 활동 ({total})</div>
+      </div>
+      <ActivityFilters filters={filters} onChange={setFilters} />
+      <div className="ao-sidepanel-content ao-activity-content">
+        {error && (
+          <div className="ao-activity-error">
+            불러오기 실패: {error}
+            <button type="button" onClick={retry}>재시도</button>
+          </div>
+        )}
+        {!error && items.length === 0 && !loading && (
+          <div className="ao-empty">최근 {filters.days}일 활동 없음</div>
+        )}
+        {items.map((item, i) => (
+          <ActivityItem
+            key={`${item.type}-${item.task_id}-${item.created_at}-${i}`}
+            item={item}
+            onSelectAgent={onSelectAgent}
+          />
+        ))}
+        {loading && <div className="ao-activity-loading">불러오는 중…</div>}
+        {hasMore && !loading && <div ref={sentinelRef} className="ao-activity-sentinel" />}
+        {!hasMore && items.length > 0 && <div className="ao-activity-end">더 이상 활동 없음</div>}
+      </div>
+    </div>
+  );
+}
diff --git a/src/pages/agent-office/components/ActivityTimeline.test.jsx b/src/pages/agent-office/components/ActivityTimeline.test.jsx
new file mode 100644
index 0000000..ba72d5a
--- /dev/null
+++ b/src/pages/agent-office/components/ActivityTimeline.test.jsx
@@ -0,0 +1,45 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { render, screen, waitFor, fireEvent } from '@testing-library/react';
+import ActivityTimeline from './ActivityTimeline.jsx';
+
+// jsdom IntersectionObserver stub
+beforeEach(() => {
+  global.IntersectionObserver = class {
+    observe() {} unobserve() {} disconnect() {}
+  };
+});
+
+const mockAgentActivity = vi.fn();
+vi.mock('../../../api', () => ({
+  agentActivity: (...args) => mockAgentActivity(...args),
+}));
+
+describe('ActivityTimeline', () => {
+  it('항목을 렌더하고 헤더에 total을 표시한다', async () => {
+    mockAgentActivity.mockResolvedValueOnce({
+      items: [{ type: 'task', agent_id: 'stock', task_id: 'a', message: 'holdings_brief', created_at: '2026-06-10T23:30:00Z', status: 'succeeded', duration_seconds: 2 }],
+      total: 1,
+    });
+    render(<ActivityTimeline refreshTrigger={0} onSelectAgent={() => {}} />);
+    await waitFor(() => expect(screen.getByText('holdings_brief')).toBeInTheDocument());
+    expect(screen.getByText(/팀 활동/)).toHaveTextContent('1');
+  });
+
+  it('빈 결과면 안내 문구를 표시한다', async () => {
+    mockAgentActivity.mockResolvedValueOnce({ items: [], total: 0 });
+    render(<ActivityTimeline refreshTrigger={0} onSelectAgent={() => {}} />);
+    await waitFor(() => expect(screen.getByText(/활동 없음/)).toBeInTheDocument());
+  });
+
+  it('항목 클릭 시 onSelectAgent가 호출된다', async () => {
+    const onSelect = vi.fn();
+    mockAgentActivity.mockResolvedValueOnce({
+      items: [{ type: 'task', agent_id: 'lotto', task_id: 'b', message: 'signal_check', created_at: '2026-06-10T23:15:00Z', status: 'succeeded' }],
+      total: 1,
+    });
+    render(<ActivityTimeline refreshTrigger={0} onSelectAgent={onSelect} />);
+    const row = await screen.findByText('signal_check');
+    fireEvent.click(row.closest('.ao-activity-item'));
+    expect(onSelect).toHaveBeenCalledWith('lotto');
+  });
+});