| Preston to Orbetello | 1,008.11 mi (1,622.40 km) |
| Preston to Oria | 1,315.02 mi (2,116.31 km) |
| Preston to Oristano | 1,092.87 mi (1,758.80 km) |
| Preston to Orta Nova | 1,207.44 mi (1,943.18 km) |
| Preston to Orte | 1,041.53 mi (1,676.18 km) |
| Preston to Ortona | 1,110.28 mi (1,786.82 km) |
| Preston to Orvieto | 1,018.85 mi (1,639.69 km) |
| Preston to Orzinuovi | 806.33 mi (1,297.66 km) |
| Preston to Osimo | 1,020.37 mi (1,642.13 km) |
| Preston to Ospitaletto | 802.49 mi (1,291.48 km) |
| Preston to Ostuni | 1,300.87 mi (2,093.55 km) |
| Preston to Ottaviano | 1,195.04 mi (1,923.23 km) |
| Preston to Ovada | 810.02 mi (1,303.61 km) |
| Preston to Ozieri | 1,060.23 mi (1,706.28 km) |
| Preston to Paceco | 1,307.79 mi (2,104.68 km) |
