| Ontario to Rancho Cordova (California) | 373.25 mi (600.68 km) |
| Ontario to Rancho Cucamonga (California) | 6.32 mi (10.18 km) |
| Ontario to Rancho Mirage (California) | 70.26 mi (113.08 km) |
| Ontario to Rancho Palos Verdes (California) | 47.64 mi (76.67 km) |
| Ontario to Rancho San Diego (California) | 96.71 mi (155.64 km) |
| Ontario to Rancho Santa Margarita (California) | 28.16 mi (45.32 km) |
| Ontario to Randallstown (Maryland) | 2,270.56 mi (3,654.12 km) |
| Ontario to Rantoul (Illinois) | 1,669.71 mi (2,687.13 km) |
| Ontario to Rapid City (South Dakota) | 1,034.63 mi (1,665.08 km) |
| Ontario to Ravenna (Ohio) | 2,034.70 mi (3,274.54 km) |
| Ontario to Raymondville (Texas) | 1,290.70 mi (2,077.19 km) |
| Ontario to Raymore (Missouri) | 1,324.43 mi (2,131.47 km) |
| Ontario to Raytown (Missouri) | 1,325.85 mi (2,133.75 km) |
| Ontario to Reading (Ohio) | 1,863.08 mi (2,998.34 km) |
| Ontario to Reading (Pennsylvania) | 2,313.22 mi (3,722.77 km) |
