| Kastamonu to Orbetello | 1,159.15 mi (1,865.47 km) |
| Kastamonu to Oria | 843.52 mi (1,357.52 km) |
| Kastamonu to Oristano | 1,319.64 mi (2,123.76 km) |
| Kastamonu to Orta Nova | 935.24 mi (1,505.12 km) |
| Kastamonu to Orte | 1,099.35 mi (1,769.23 km) |
| Kastamonu to Ortona | 997.15 mi (1,604.75 km) |
| Kastamonu to Orvieto | 1,112.44 mi (1,790.29 km) |
| Kastamonu to Orzinuovi | 1,224.16 mi (1,970.09 km) |
| Kastamonu to Osimo | 1,042.44 mi (1,677.65 km) |
| Kastamonu to Ospitaletto | 1,218.32 mi (1,960.70 km) |
| Kastamonu to Ostuni | 843.63 mi (1,357.70 km) |
| Kastamonu to Ottaviano | 1,003.20 mi (1,614.50 km) |
| Kastamonu to Ovada | 1,284.24 mi (2,066.79 km) |
| Kastamonu to Ozieri | 1,288.94 mi (2,074.35 km) |
| Kastamonu to Paceco | 1,149.73 mi (1,850.31 km) |
