diff --git a/relay/src/middleware/admin-auth.ts b/relay/src/middleware/admin-auth.ts
index 36f03513..42fe5bb0 100644
--- a/relay/src/middleware/admin-auth.ts
+++ b/relay/src/middleware/admin-auth.ts
@@ -5,6 +5,7 @@
  */
 
 import { Request, Response, NextFunction } from "express";
+import { isRateLimited, recordFailedAttempt } from "./token-auth";
 import { secureCompare, hashToken } from "../utils/security";
 import { authConfig } from "../config";
 import { loggers } from "../utils/logger";
@@ -27,6 +28,19 @@ function getAdminPasswordHash(): string | null {
  * Uses timing-safe comparison to prevent timing attacks
  */
 export function adminAuthMiddleware(req: Request, res: Response, next: NextFunction): void {
+  const clientIp = req.ip || req.connection?.remoteAddress || req.socket?.remoteAddress || "unknown";
+
+  if (isRateLimited(clientIp)) {
+    log.warn(
+      { ip: clientIp, path: req.path },
+      "Admin auth failed - rate limited"
+    );
+    res.status(429).json({
+      success: false,
+      error: "Too many failed authentication attempts. Please try again later.",
+    });
+    return;
+  }
   // Check Authorization header (Bearer token)
   const authHeader = req.headers["authorization"];
   const bearerToken = authHeader && authHeader.split(" ")[1];
@@ -45,6 +59,7 @@ export function adminAuthMiddleware(req: Request, res: Response, next: NextFunct
       },
       "Admin auth failed - no token"
     );
+    recordFailedAttempt(clientIp);
     res.status(401).json({
       success: false,
       error: "Unauthorized - Admin token required",
@@ -83,6 +98,7 @@ export function adminAuthMiddleware(req: Request, res: Response, next: NextFunct
       },
       "Admin auth failed - invalid token"
     );
+    recordFailedAttempt(clientIp);
     res.status(401).json({
       success: false,
       error: "Unauthorized - Invalid admin token",
diff --git a/relay/src/tests/admin-auth.test.ts b/relay/src/tests/admin-auth.test.ts
new file mode 100644
index 00000000..0ef25213
--- /dev/null
+++ b/relay/src/tests/admin-auth.test.ts
@@ -0,0 +1,86 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { adminAuthMiddleware } from "../middleware/admin-auth";
+import { isRateLimited, recordFailedAttempt } from "../middleware/token-auth";
+import { Request, Response, NextFunction } from "express";
+
+// Mock dependencies
+vi.mock("../utils/logger", () => ({
+  loggers: {
+    server: {
+      info: vi.fn(),
+      warn: vi.fn(),
+      error: vi.fn(),
+      debug: vi.fn(),
+    },
+  },
+}));
+
+vi.mock("../config", () => ({
+  authConfig: { adminPassword: "test-admin-password", strictSessionIp: true },
+}));
+
+vi.mock("../middleware/token-auth", () => {
+  return {
+    isRateLimited: vi.fn(),
+    recordFailedAttempt: vi.fn(),
+  };
+});
+
+describe("adminAuthMiddleware rate limiting", () => {
+  let mockReq: Partial<Request>;
+  let mockRes: Partial<Response>;
+  let mockNext: NextFunction;
+
+  beforeEach(() => {
+    vi.useFakeTimers();
+    mockReq = {
+      headers: {},
+      ip: "192.168.1.100",
+      path: "/api/system/stats",
+    };
+    mockRes = {
+      status: vi.fn().mockReturnThis(),
+      json: vi.fn(),
+    };
+    mockNext = vi.fn();
+
+    vi.clearAllMocks();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("should block requests when rate limited", () => {
+    vi.mocked(isRateLimited).mockReturnValueOnce(true);
+
+    adminAuthMiddleware(mockReq as Request, mockRes as Response, mockNext);
+
+    expect(isRateLimited).toHaveBeenCalledWith(mockReq.ip);
+    expect(mockRes.status).toHaveBeenCalledWith(429);
+    expect(mockRes.json).toHaveBeenCalledWith({
+      success: false,
+      error: "Too many failed authentication attempts. Please try again later.",
+    });
+    expect(mockNext).not.toHaveBeenCalled();
+  });
+
+  it("should record failed attempt when no token is provided", () => {
+    vi.mocked(isRateLimited).mockReturnValueOnce(false);
+
+    adminAuthMiddleware(mockReq as Request, mockRes as Response, mockNext);
+
+    expect(recordFailedAttempt).toHaveBeenCalledWith(mockReq.ip);
+    expect(mockRes.status).toHaveBeenCalledWith(401);
+  });
+
+  it("should record failed attempt when an invalid token is provided", () => {
+    vi.mocked(isRateLimited).mockReturnValueOnce(false);
+    mockReq.headers = { authorization: "Bearer invalid-token" };
+
+    adminAuthMiddleware(mockReq as Request, mockRes as Response, mockNext);
+
+    expect(recordFailedAttempt).toHaveBeenCalledWith(mockReq.ip);
+    expect(mockRes.status).toHaveBeenCalledWith(401);
+  });
+});