| Skien to Orbetello | 1,160.78 mi (1,868.09 km) |
| Skien to Oria | 1,339.49 mi (2,155.70 km) |
| Skien to Oristano | 1,334.32 mi (2,147.38 km) |
| Skien to Orta Nova | 1,263.50 mi (2,033.40 km) |
| Skien to Orte | 1,163.49 mi (1,872.45 km) |
| Skien to Ortona | 1,183.11 mi (1,904.04 km) |
| Skien to Orvieto | 1,144.55 mi (1,841.97 km) |
| Skien to Orzinuovi | 954.18 mi (1,535.60 km) |
| Skien to Osimo | 1,099.17 mi (1,768.94 km) |
| Skien to Ospitaletto | 943.57 mi (1,518.52 km) |
| Skien to Ostuni | 1,323.18 mi (2,129.46 km) |
| Skien to Ottaviano | 1,286.27 mi (2,070.05 km) |
| Skien to Ovada | 1,007.33 mi (1,621.14 km) |
| Skien to Ozieri | 1,286.96 mi (2,071.16 km) |
| Skien to Paceco | 1,472.52 mi (2,369.78 km) |
