| Ruislip to Orbetello | 834.36 mi (1,342.77 km) |
| Ruislip to Oria | 1,150.38 mi (1,851.36 km) |
| Ruislip to Oristano | 914.67 mi (1,472.01 km) |
| Ruislip to Orta Nova | 1,040.58 mi (1,674.65 km) |
| Ruislip to Orte | 870.10 mi (1,400.30 km) |
| Ruislip to Ortona | 943.08 mi (1,517.74 km) |
| Ruislip to Orvieto | 847.42 mi (1,363.80 km) |
| Ruislip to Orzinuovi | 637.21 mi (1,025.49 km) |
| Ruislip to Osimo | 854.29 mi (1,374.84 km) |
| Ruislip to Ospitaletto | 634.37 mi (1,020.91 km) |
| Ruislip to Ostuni | 1,136.73 mi (1,829.38 km) |
| Ruislip to Ottaviano | 1,024.50 mi (1,648.77 km) |
| Ruislip to Ovada | 635.58 mi (1,022.87 km) |
| Ruislip to Ozieri | 882.23 mi (1,419.81 km) |
| Ruislip to Paceco | 1,130.95 mi (1,820.09 km) |
