| Chatham to Orbetello | 795.51 mi (1,280.24 km) |
| Chatham to Oria | 1,108.68 mi (1,784.25 km) |
| Chatham to Oristano | 881.61 mi (1,418.82 km) |
| Chatham to Orta Nova | 999.32 mi (1,608.26 km) |
| Chatham to Orte | 830.18 mi (1,336.05 km) |
| Chatham to Ortona | 901.87 mi (1,451.43 km) |
| Chatham to Orvieto | 807.50 mi (1,299.54 km) |
| Chatham to Orzinuovi | 596.38 mi (959.79 km) |
| Chatham to Osimo | 812.79 mi (1,308.06 km) |
| Chatham to Ospitaletto | 593.25 mi (954.74 km) |
| Chatham to Ostuni | 1,094.93 mi (1,762.12 km) |
| Chatham to Ottaviano | 984.29 mi (1,584.07 km) |
| Chatham to Ovada | 597.08 mi (960.91 km) |
| Chatham to Ozieri | 847.93 mi (1,364.61 km) |
| Chatham to Paceco | 1,094.50 mi (1,761.43 km) |
