| Ontario to Oxford (Alabama) | 1,814.74 mi (2,920.54 km) |
| Ontario to Oxford (Mississippi) | 1,599.22 mi (2,573.70 km) |
| Ontario to Oxford (Ohio) | 1,846.80 mi (2,972.14 km) |
| Ontario to Oxnard (California) | 90.75 mi (146.05 km) |
| Ontario to Oxon Hill (Maryland) | 2,264.33 mi (3,644.08 km) |
| Ontario to Ozark (Alabama) | 1,858.33 mi (2,990.69 km) |
| Ontario to Ozark (Missouri) | 1,382.98 mi (2,225.69 km) |
| Ontario to Pace (Florida) | 1,786.19 mi (2,874.60 km) |
| Ontario to Pacific Grove (California) | 301.69 mi (485.52 km) |
| Ontario to Pacifica (California) | 367.86 mi (592.01 km) |
| Ontario to Paducah (Kentucky) | 1,635.05 mi (2,631.36 km) |
| Ontario to Pahrump (Nevada) | 176.18 mi (283.53 km) |
| Ontario to Painesville (Ohio) | 2,035.86 mi (3,276.40 km) |
| Ontario to Palatine (Illinois) | 1,691.91 mi (2,722.87 km) |
| Ontario to Palatka (Florida) | 2,120.01 mi (3,411.82 km) |
