| Sumter to Oskaloosa (Iowa) | 839.68 mi (1,351.33 km) |
| Sumter to Oswego (Illinois) | 688.06 mi (1,107.33 km) |
| Sumter to Oswego (New York) | 689.73 mi (1,110.01 km) |
| Sumter to Otsego (Minnesota) | 1,049.98 mi (1,689.78 km) |
| Sumter to Ottawa (Illinois) | 688.80 mi (1,108.51 km) |
| Sumter to Ottawa (Kansas) | 887.45 mi (1,428.21 km) |
| Sumter to Ottumwa (Iowa) | 819.73 mi (1,319.23 km) |
| Sumter to Overland (Missouri) | 644.78 mi (1,037.68 km) |
| Sumter to Overland Park (Kansas) | 863.93 mi (1,390.36 km) |
| Sumter to Overlea (Maryland) | 431.92 mi (695.10 km) |
| Sumter to Oviedo (Florida) | 367.89 mi (592.06 km) |
| Sumter to Owasso (Oklahoma) | 886.50 mi (1,426.68 km) |
| Sumter to Owatonna (Minnesota) | 981.09 mi (1,578.91 km) |
| Sumter to Owensboro (Kentucky) | 459.60 mi (739.65 km) |
| Sumter to Owings Mills (Maryland) | 427.45 mi (687.91 km) |
