Post Offices in & near Petersburg, Illinois. Operating hours, locations, phone/fax number, services information.
Post Office in O Fallon, Illinois on S Lincoln Ave. Operating hours, phone number, services information, and other locations.
Address: 1111 S Lincoln Ave, O Fallon, IL 62269
Phone: 618-632-4691
Toll-Free: 1-800-Ask-USPS® (275-8777)
TTY: 877-889-2457
