| Ontario to Cadillac (Michigan) | 1,848.73 mi (2,975.24 km) |
| Ontario to Caguas (Puerto Rico) | 3,341.85 mi (5,378.18 km) |
| Ontario to Cahokia (Illinois) | 1,552.80 mi (2,498.99 km) |
| Ontario to Calabasas (California) | 61.17 mi (98.45 km) |
| Ontario to Caldwell (Idaho) | 665.65 mi (1,071.26 km) |
| Ontario to Caledonia (Wisconsin) | 1,708.55 mi (2,749.64 km) |
| Ontario to Calera (Alabama) | 1,770.81 mi (2,849.84 km) |
| Ontario to Calexico (California) | 153.65 mi (247.28 km) |
| Ontario to Calhoun (Georgia) | 1,857.45 mi (2,989.28 km) |
| Ontario to California (Maryland) | 2,293.00 mi (3,690.23 km) |
| Ontario to California City (California) | 78.74 mi (126.73 km) |
| Ontario to Callaway (Florida) | 1,887.67 mi (3,037.91 km) |
| Ontario to Calumet City (Illinois) | 1,711.69 mi (2,754.70 km) |
| Ontario to Calverton (Maryland) | 2,264.22 mi (3,643.90 km) |
| Ontario to Camano (Washington) | 1,009.20 mi (1,624.16 km) |
