| Rickmansworth to Orbetello | 838.39 mi (1,349.26 km) |
| Rickmansworth to Oria | 1,153.99 mi (1,857.17 km) |
| Rickmansworth to Oristano | 919.07 mi (1,479.10 km) |
| Rickmansworth to Orta Nova | 1,044.28 mi (1,680.61 km) |
| Rickmansworth to Orte | 874.01 mi (1,406.58 km) |
| Rickmansworth to Ortona | 946.79 mi (1,523.71 km) |
| Rickmansworth to Orvieto | 851.33 mi (1,370.08 km) |
| Rickmansworth to Orzinuovi | 640.98 mi (1,031.55 km) |
| Rickmansworth to Osimo | 857.94 mi (1,380.72 km) |
| Rickmansworth to Ospitaletto | 638.08 mi (1,026.89 km) |
| Rickmansworth to Ostuni | 1,140.31 mi (1,835.16 km) |
| Rickmansworth to Ottaviano | 1,028.37 mi (1,655.00 km) |
| Rickmansworth to Ovada | 639.64 mi (1,029.40 km) |
| Rickmansworth to Ozieri | 886.58 mi (1,426.82 km) |
| Rickmansworth to Paceco | 1,135.19 mi (1,826.91 km) |
