| Trowbridge to Orbetello | 879.59 mi (1,415.56 km) |
| Trowbridge to Oria | 1,205.26 mi (1,939.69 km) |
| Trowbridge to Oristano | 943.53 mi (1,518.47 km) |
| Trowbridge to Orta Nova | 1,093.75 mi (1,760.22 km) |
| Trowbridge to Orte | 918.71 mi (1,478.53 km) |
| Trowbridge to Ortona | 996.24 mi (1,603.29 km) |
| Trowbridge to Orvieto | 896.12 mi (1,442.17 km) |
| Trowbridge to Orzinuovi | 689.94 mi (1,110.35 km) |
| Trowbridge to Osimo | 908.86 mi (1,462.67 km) |
| Trowbridge to Ospitaletto | 688.19 mi (1,107.53 km) |
| Trowbridge to Ostuni | 1,192.06 mi (1,918.43 km) |
| Trowbridge to Ottaviano | 1,073.68 mi (1,727.93 km) |
| Trowbridge to Ovada | 680.69 mi (1,095.47 km) |
| Trowbridge to Ozieri | 914.41 mi (1,471.60 km) |
| Trowbridge to Paceco | 1,168.12 mi (1,879.91 km) |
