US Post Office is located at 7230 171St St, Tinley Park, IL. This business specializes in Post Offices. US Post Office is open Mon, 8am-7pm ; Tue, 8am-7pm ; Wed, 8am-7pm ; Thu, 8am-7pm ; Fri, 8am-7pm ; Sat, 8am-3pm ; Sun, Closed. and accepts American Express, Discover and Visa.