| Ontario to Cullman (Alabama) | 1,753.29 mi (2,821.64 km) |
| Ontario to Culpeper (Virginia) | 2,210.75 mi (3,557.86 km) |
| Ontario to Culver City (California) | 45.32 mi (72.94 km) |
| Ontario to Cumberland (Maryland) | 2,165.46 mi (3,484.97 km) |
| Ontario to Cupertino (California) | 336.65 mi (541.78 km) |
| Ontario to Cutler Bay (Florida) | 2,296.04 mi (3,695.11 km) |
| Ontario to Cutlerville (Michigan) | 1,819.05 mi (2,927.48 km) |
| Ontario to Cuyahoga Falls (Ohio) | 2,020.24 mi (3,251.26 km) |
| Ontario to Cypress (California) | 29.15 mi (46.91 km) |
| Ontario to Cypress Gardens (Florida) | 2,156.04 mi (3,469.81 km) |
| Ontario to Cypress Lake (Florida) | 2,180.63 mi (3,509.39 km) |
| Ontario to D'Iberville (Mississippi) | 1,689.68 mi (2,719.27 km) |
| Ontario to Dakota Ridge (Colorado) | 789.12 mi (1,269.96 km) |
| Ontario to Dale City (Virginia) | 2,245.03 mi (3,613.03 km) |
| Ontario to Dallas (Georgia) | 1,869.16 mi (3,008.12 km) |
