| Milford Haven to Orbetello | 993.91 mi (1,599.55 km) |
| Milford Haven to Oria | 1,325.25 mi (2,132.78 km) |
| Milford Haven to Oristano | 1,043.74 mi (1,679.74 km) |
| Milford Haven to Orta Nova | 1,212.86 mi (1,951.91 km) |
| Milford Haven to Orte | 1,035.26 mi (1,666.09 km) |
| Milford Haven to Ortona | 1,115.49 mi (1,795.22 km) |
| Milford Haven to Orvieto | 1,012.79 mi (1,629.93 km) |
| Milford Haven to Orzinuovi | 809.67 mi (1,303.04 km) |
| Milford Haven to Osimo | 1,029.08 mi (1,656.14 km) |
| Milford Haven to Ospitaletto | 808.50 mi (1,301.16 km) |
| Milford Haven to Ostuni | 1,312.31 mi (2,111.96 km) |
| Milford Haven to Ottaviano | 1,190.26 mi (1,915.55 km) |
| Milford Haven to Ovada | 795.80 mi (1,280.72 km) |
| Milford Haven to Ozieri | 1,017.89 mi (1,638.13 km) |
| Milford Haven to Paceco | 1,275.02 mi (2,051.94 km) |
