| Portchester to Orbetello | 822.15 mi (1,323.12 km) |
| Portchester to Oria | 1,147.78 mi (1,847.18 km) |
| Portchester to Oristano | 888.89 mi (1,430.52 km) |
| Portchester to Orta Nova | 1,036.18 mi (1,667.57 km) |
| Portchester to Orte | 861.11 mi (1,385.82 km) |
| Portchester to Ortona | 938.67 mi (1,510.65 km) |
| Portchester to Orvieto | 838.51 mi (1,349.45 km) |
| Portchester to Orzinuovi | 632.40 mi (1,017.74 km) |
| Portchester to Osimo | 851.39 mi (1,370.19 km) |
| Portchester to Ospitaletto | 630.71 mi (1,015.03 km) |
| Portchester to Ostuni | 1,134.61 mi (1,825.98 km) |
| Portchester to Ottaviano | 1,016.07 mi (1,635.21 km) |
| Portchester to Ovada | 623.21 mi (1,002.96 km) |
| Portchester to Ozieri | 858.96 mi (1,382.36 km) |
| Portchester to Paceco | 1,111.77 mi (1,789.23 km) |
