| Mariehamn to Oria | 1,357.83 mi (2,185.21 km) |
| Mariehamn to Oristano | 1,478.55 mi (2,379.49 km) |
| Mariehamn to Orta Nova | 1,309.27 mi (2,107.06 km) |
| Mariehamn to Orte | 1,259.74 mi (2,027.36 km) |
| Mariehamn to Ortona | 1,248.50 mi (2,009.27 km) |
| Mariehamn to Orvieto | 1,245.33 mi (2,004.17 km) |
| Mariehamn to Orzinuovi | 1,095.56 mi (1,763.13 km) |
| Mariehamn to Osimo | 1,179.38 mi (1,898.03 km) |
| Mariehamn to Ospitaletto | 1,083.24 mi (1,743.30 km) |
| Mariehamn to Ostuni | 1,341.90 mi (2,159.57 km) |
| Mariehamn to Ottaviano | 1,350.41 mi (2,173.27 km) |
| Mariehamn to Ovada | 1,165.78 mi (1,876.14 km) |
| Mariehamn to Ozieri | 1,427.52 mi (2,297.37 km) |
| Mariehamn to Paceco | 1,562.01 mi (2,513.82 km) |
| Mariehamn to Pachino | 1,629.74 mi (2,622.82 km) |
