| Ontario to Altus (Oklahoma) | 1,043.38 mi (1,679.16 km) |
| Ontario to Alum Rock (California) | 329.97 mi (531.04 km) |
| Ontario to Alvin (Texas) | 1,347.28 mi (2,168.24 km) |
| Ontario to Amarillo (Texas) | 899.58 mi (1,447.73 km) |
| Ontario to Amelia (Ohio) | 1,874.33 mi (3,016.45 km) |
| Ontario to American Canyon (California) | 386.23 mi (621.58 km) |
| Ontario to American Fork (Utah) | 542.00 mi (872.27 km) |
| Ontario to Americus (Georgia) | 1,929.36 mi (3,105.00 km) |
| Ontario to Ames (Iowa) | 1,411.00 mi (2,270.79 km) |
| Ontario to Amherst (Ohio) | 1,984.22 mi (3,193.30 km) |
| Ontario to Ammon (Idaho) | 719.03 mi (1,157.16 km) |
| Ontario to Amsterdam (New York) | 2,398.71 mi (3,860.36 km) |
| Ontario to Anacortes (Washington) | 1,031.23 mi (1,659.60 km) |
| Ontario to Anaheim (California) | 19.96 mi (32.13 km) |
| Ontario to Anchorage (Alaska) | 2,333.87 mi (3,756.00 km) |
