| Tadley to Orbetello | 845.79 mi (1,361.16 km) |
| Tadley to Oria | 1,167.02 mi (1,878.13 km) |
| Tadley to Oristano | 918.13 mi (1,477.59 km) |
| Tadley to Orta Nova | 1,056.26 mi (1,699.89 km) |
| Tadley to Orte | 883.30 mi (1,421.53 km) |
| Tadley to Ortona | 958.71 mi (1,542.90 km) |
| Tadley to Orvieto | 860.65 mi (1,385.08 km) |
| Tadley to Orzinuovi | 652.41 mi (1,049.96 km) |
| Tadley to Osimo | 870.64 mi (1,401.16 km) |
| Tadley to Ospitaletto | 650.16 mi (1,046.33 km) |
| Tadley to Ostuni | 1,153.60 mi (1,856.54 km) |
| Tadley to Ottaviano | 1,038.07 mi (1,670.61 km) |
| Tadley to Ovada | 646.76 mi (1,040.87 km) |
| Tadley to Ozieri | 887.25 mi (1,427.89 km) |
| Tadley to Paceco | 1,138.53 mi (1,832.29 km) |
