| Hammersmith to Orbetello | 823.90 mi (1,325.94 km) |
| Hammersmith to Oria | 1,139.68 mi (1,834.15 km) |
| Hammersmith to Oristano | 905.05 mi (1,456.54 km) |
| Hammersmith to Orta Nova | 1,029.90 mi (1,657.47 km) |
| Hammersmith to Orte | 859.53 mi (1,383.28 km) |
| Hammersmith to Ortona | 932.41 mi (1,500.56 km) |
| Hammersmith to Orvieto | 836.85 mi (1,346.78 km) |
| Hammersmith to Orzinuovi | 626.56 mi (1,008.35 km) |
| Hammersmith to Osimo | 843.60 mi (1,357.64 km) |
| Hammersmith to Ospitaletto | 623.70 mi (1,003.74 km) |
| Hammersmith to Ostuni | 1,126.03 mi (1,812.16 km) |
| Hammersmith to Ottaviano | 1,013.90 mi (1,631.71 km) |
| Hammersmith to Ovada | 625.16 mi (1,006.09 km) |
| Hammersmith to Ozieri | 872.41 mi (1,404.01 km) |
| Hammersmith to Paceco | 1,120.82 mi (1,803.78 km) |
