| Ontario to Ridgeland (Mississippi) | 1,586.11 mi (2,552.59 km) |
| Ontario to Ridgewood (New Jersey) | 2,406.04 mi (3,872.15 km) |
| Ontario to Rifle (Colorado) | 662.91 mi (1,066.85 km) |
| Ontario to Rincon (Georgia) | 2,096.00 mi (3,373.19 km) |
| Ontario to Ringwood (New Jersey) | 2,397.19 mi (3,857.91 km) |
| Ontario to Río Grande (Puerto Rico) | 3,348.23 mi (5,388.45 km) |
| Ontario to Rio Grande City (Texas) | 1,237.50 mi (1,991.57 km) |
| Ontario to Rio Linda (California) | 385.50 mi (620.40 km) |
| Ontario to Rio Rancho (New Mexico) | 625.55 mi (1,006.72 km) |
| Ontario to Rio Rico (Arizona) | 422.63 mi (680.16 km) |
| Ontario to Ripon (California) | 322.99 mi (519.80 km) |
| Ontario to River Edge (New Jersey) | 2,410.09 mi (3,878.67 km) |
| Ontario to River Falls (Wisconsin) | 1,519.21 mi (2,444.92 km) |
| Ontario to River Forest (Illinois) | 1,700.80 mi (2,737.18 km) |
| Ontario to River Grove (Illinois) | 1,700.17 mi (2,736.17 km) |
