| Ontario to Cibolo (Texas) | 1,178.06 mi (1,895.90 km) |
| Ontario to Cicero (Illinois) | 1,703.33 mi (2,741.25 km) |
| Ontario to Cimarron Hills (Colorado) | 789.89 mi (1,271.20 km) |
| Ontario to Cincinnati (Ohio) | 1,859.13 mi (2,991.98 km) |
| Ontario to Cinco Ranch (Texas) | 1,312.79 mi (2,112.74 km) |
| Ontario to Circleville (Ohio) | 1,943.38 mi (3,127.56 km) |
| Ontario to Citrus (California) | 17.02 mi (27.40 km) |
| Ontario to Citrus Heights (California) | 381.26 mi (613.58 km) |
| Ontario to Citrus Park (Florida) | 2,104.18 mi (3,386.35 km) |
| Ontario to Claiborne (Louisiana) | 1,467.39 mi (2,361.54 km) |
| Ontario to Claremont (California) | 8.64 mi (13.90 km) |
| Ontario to Claremont (New Hampshire) | 2,491.99 mi (4,010.47 km) |
| Ontario to Claremore (Oklahoma) | 1,249.45 mi (2,010.80 km) |
| Ontario to Clarksburg (Maryland) | 2,246.48 mi (3,615.37 km) |
| Ontario to Clarksburg (West Virginia) | 2,082.90 mi (3,352.11 km) |
