| Cahokia to Oswego (Illinois) | 236.40 mi (380.46 km) |
| Cahokia to Oswego (New York) | 787.78 mi (1,267.81 km) |
| Cahokia to Otsego (Minnesota) | 495.51 mi (797.45 km) |
| Cahokia to Ottawa (Illinois) | 205.68 mi (331.02 km) |
| Cahokia to Ottawa (Kansas) | 274.58 mi (441.90 km) |
| Cahokia to Ottumwa (Iowa) | 207.09 mi (333.28 km) |
| Cahokia to Overland (Missouri) | 13.69 mi (22.03 km) |
| Cahokia to Overland Park (Kansas) | 243.97 mi (392.63 km) |
| Cahokia to Overlea (Maryland) | 735.31 mi (1,183.37 km) |
| Cahokia to Oviedo (Florida) | 857.06 mi (1,379.30 km) |
| Cahokia to Owasso (Oklahoma) | 347.65 mi (559.49 km) |
| Cahokia to Owatonna (Minnesota) | 413.27 mi (665.10 km) |
| Cahokia to Owensboro (Kentucky) | 175.45 mi (282.36 km) |
| Cahokia to Owings Mills (Maryland) | 720.70 mi (1,159.86 km) |
| Cahokia to Owosso (Michigan) | 438.36 mi (705.47 km) |
