| Caister-on-Sea to Orbetello | 831.05 mi (1,337.45 km) |
| Caister-on-Sea to Oria | 1,124.23 mi (1,809.27 km) |
| Caister-on-Sea to Oristano | 938.50 mi (1,510.37 km) |
| Caister-on-Sea to Orta Nova | 1,018.98 mi (1,639.89 km) |
| Caister-on-Sea to Orte | 859.74 mi (1,383.62 km) |
| Caister-on-Sea to Ortona | 922.54 mi (1,484.68 km) |
| Caister-on-Sea to Orvieto | 837.21 mi (1,347.37 km) |
| Caister-on-Sea to Orzinuovi | 622.88 mi (1,002.42 km) |
| Caister-on-Sea to Osimo | 831.89 mi (1,338.80 km) |
| Caister-on-Sea to Ospitaletto | 617.77 mi (994.21 km) |
| Caister-on-Sea to Ostuni | 1,109.72 mi (1,785.93 km) |
| Caister-on-Sea to Ottaviano | 1,011.13 mi (1,627.26 km) |
| Caister-on-Sea to Ovada | 636.54 mi (1,024.41 km) |
| Caister-on-Sea to Ozieri | 901.15 mi (1,450.26 km) |
| Caister-on-Sea to Paceco | 1,138.72 mi (1,832.59 km) |
