| Business | Phone |
| Middendorf-Kredell Library 2750 Highway K, O Fallon 63368 | (636) 978-7926 |
| Library Express 7435 Village Center Dr, O Fallon 63368 | (636) 561-3385 |
| Deer Run Branch 1300 N Main St, O Fallon 63366 | (636) 980-1332 |
| Deer Run Library 1300 N Main St, O Fallon 63366 | (636) 978-3251 |