Post offices serve all communities within a county, from city branch locations to rural contract postal units that serve smaller towns and unincorporated areas with essential mail services. There are 12 Post Office locations in Williamson County, Illinois.

Residents of Williamson County should be aware that rural post offices and contract postal units may have limited hours compared to full-service branches. USPS provides a free package pickup service for all residents, including those in rural areas, which can eliminate the need to travel to a post office for outgoing packages.

List of Williamson County, Illinois Post Office

Cambria Post Office

View Details Call Now (618) 985-6501

Cambria Post Office

Address
Get Direction
Hours

Carterville Post Office

View Details Call Now (618) 985-2380

Carterville Post Office

Address
Get Direction
Hours

Colp Post Office

Address
Get Direction
Hours

Creal Springs Post Office

View Details Call Now (618) 996-2191

Creal Springs Post Office

Address
Get Direction
Hours

Marion Center Post Office

View Details Call Now (618) 993-8052

Marion Center Post Office

Address
Get Direction
Hours

Johnston City Post Office

View Details Call Now (618) 983-5001

Johnston City Post Office

Address
Get Direction
Hours

Marion Post Office

View Details Call Now (618) 993-2933

Marion Post Office

Address
Get Direction
Hours

Hurst Post Office

Address
Get Direction
Hours

Freeman Spur Post Office

View Details Call Now (618) 988-1454

Freeman Spur Post Office

Address
Get Direction
Hours

Herrin Post Office

View Details Call Now (618) 942-4845

Herrin Post Office

Address
Get Direction
Hours

Pittsburg Post Office

View Details Call Now (618) 993-8643

Pittsburg Post Office

Address
Get Direction
Hours

Energy Post Office

View Details Call Now (618) 942-3300

Energy Post Office

Address
Get Direction
Hours

Residents of Williamson County can use the USPS online location finder to identify the nearest post office, rural branch, or contract postal unit and check their individual hours. Enrolling in USPS Informed Delivery is free and lets all county residents preview incoming mail and packages via email or the USPS app each morning before delivery.

You may also find Post Office locations in neighboring counties including Williamson, Franklin, Jackson.