Find Post office Near Me in O'Brien Welcome to our new site: catalog of Post office of O'Brien, Texas. Find Post office Near Me. Closed now United States Postal Service Establishment Finance Post office +1 800-275-8777 601 9th Street, O'Brien, TX 79539 TEXAS-PAGES.COM O'Brien Post office Types of organizations in O'Brien, Texas All types Establishment Finance Post office School