| Dartford to Orbetello | 807.93 mi (1,300.24 km) |
| Dartford to Oria | 1,122.00 mi (1,805.68 km) |
| Dartford to Oristano | 892.20 mi (1,435.86 km) |
| Dartford to Orta Nova | 1,012.51 mi (1,629.47 km) |
| Dartford to Orte | 842.94 mi (1,356.59 km) |
| Dartford to Ortona | 915.04 mi (1,472.61 km) |
| Dartford to Orvieto | 820.26 mi (1,320.08 km) |
| Dartford to Orzinuovi | 609.42 mi (980.76 km) |
| Dartford to Osimo | 826.04 mi (1,329.38 km) |
| Dartford to Ospitaletto | 606.38 mi (975.87 km) |
| Dartford to Ostuni | 1,108.28 mi (1,783.60 km) |
| Dartford to Ottaviano | 997.15 mi (1,604.76 km) |
| Dartford to Ovada | 609.38 mi (980.70 km) |
| Dartford to Ozieri | 858.91 mi (1,382.29 km) |
| Dartford to Paceco | 1,106.18 mi (1,780.23 km) |
