| Champaign to Olympia Heights (Florida) | 1,094.42 mi (1,761.29 km) |
| Champaign to Omaha (Nebraska) | 415.06 mi (667.98 km) |
| Champaign to On Top of the World Designated Place (Florida) | 832.79 mi (1,340.24 km) |
| Champaign to Onalaska (Wisconsin) | 301.10 mi (484.57 km) |
| Champaign to Oneida (New York) | 682.26 mi (1,097.99 km) |
| Champaign to Oneonta (New York) | 703.72 mi (1,132.54 km) |
| Champaign to Ontario (California) | 1,662.23 mi (2,675.10 km) |
| Champaign to Ontario (Oregon) | 1,488.88 mi (2,396.13 km) |
| Champaign to Opa-locka (Florida) | 1,085.27 mi (1,746.58 km) |
| Champaign to Opelika (Alabama) | 539.48 mi (868.21 km) |
| Champaign to Opelousas (Louisiana) | 696.25 mi (1,120.50 km) |
| Champaign to Orange (California) | 1,680.04 mi (2,703.76 km) |
| Champaign to Orange (Texas) | 756.39 mi (1,217.29 km) |
| Champaign to Orange City (Florida) | 868.03 mi (1,396.97 km) |
| Champaign to Orangeburg (South Carolina) | 613.69 mi (987.64 km) |
