Ontario Main Post Office

Post office

1555 E. Holt Blvd, Ontario, CA 91761

(909) 933-3837

Hours: Monday-Friday_9am-3pm. Saturday_9am-11:45am by appointment only. Please call (909)933-3837 for more information.

Appointment required

Hours and addresses come from the State Department listing, updated November 2, 2026.

Book at USPS Directions Facilities in Ontario Facilities in California

Ontario Main Post Office accepts new U.S. passport applications in person in Ontario, CA. First-time and child visits are booked on the USPS scheduler. Search ZIP 91761. How to apply · How to renew