| Killingworth to Orbetello | 1,043.09 mi (1,678.70 km) |
| Killingworth to Oria | 1,333.57 mi (2,146.18 km) |
| Killingworth to Oristano | 1,144.80 mi (1,842.38 km) |
| Killingworth to Orta Nova | 1,229.60 mi (1,978.86 km) |
| Killingworth to Orte | 1,071.85 mi (1,724.98 km) |
| Killingworth to Ortona | 1,133.52 mi (1,824.22 km) |
| Killingworth to Orvieto | 1,049.34 mi (1,688.75 km) |
| Killingworth to Orzinuovi | 834.96 mi (1,343.73 km) |
| Killingworth to Osimo | 1,042.70 mi (1,678.06 km) |
| Killingworth to Ospitaletto | 829.73 mi (1,335.32 km) |
| Killingworth to Ostuni | 1,318.85 mi (2,122.49 km) |
| Killingworth to Ottaviano | 1,222.97 mi (1,968.18 km) |
| Killingworth to Ovada | 847.96 mi (1,364.66 km) |
| Killingworth to Ozieri | 1,109.12 mi (1,784.95 km) |
| Killingworth to Paceco | 1,349.75 mi (2,172.21 km) |
