Post Offices List in St. Clair County, Missouri:
| Appleton City Post Office | 119 W 4th St, Appleton City, MO 64724 |
| Collins Post Office | 1312 Main St, Collins, MO 64738 |
| Lowry City Post Office | 204 S Main St, Lowry City, MO 64763 |
| Osceola Post Office | 565 3rd St, Osceola, MO 64776 |
| Roscoe Post Office | 100 Pecan St, Roscoe, MO 64781 |