| Ontario to Rosemont (California) | 374.91 mi (603.36 km) |
| Ontario to Rosemount (Minnesota) | 1,496.17 mi (2,407.86 km) |
| Ontario to Rosenberg (Texas) | 1,313.66 mi (2,114.13 km) |
| Ontario to Roseville (California) | 386.55 mi (622.09 km) |
| Ontario to Roseville (Michigan) | 1,954.02 mi (3,144.69 km) |
| Ontario to Roseville (Minnesota) | 1,498.96 mi (2,412.35 km) |
| Ontario to Rossmoor (California) | 32.22 mi (51.85 km) |
| Ontario to Rossville (Maryland) | 2,287.99 mi (3,682.17 km) |
| Ontario to Roswell (Georgia) | 1,895.44 mi (3,050.42 km) |
| Ontario to Roswell (New Mexico) | 752.54 mi (1,211.10 km) |
| Ontario to Round Lake (Illinois) | 1,691.38 mi (2,722.01 km) |
| Ontario to Round Lake Beach (Illinois) | 1,693.05 mi (2,724.71 km) |
| Ontario to Round Rock (Texas) | 1,187.84 mi (1,911.64 km) |
| Ontario to Rowland Heights (California) | 16.97 mi (27.31 km) |
| Ontario to Rowlett (Texas) | 1,213.91 mi (1,953.60 km) |
