| Mariehamn to Navodari | 1,148.18 mi (1,847.82 km) |
| Mariehamn to Negresti-Oas | 856.57 mi (1,378.52 km) |
| Mariehamn to Nehoiu | 1,052.04 mi (1,693.09 km) |
| Mariehamn to Ocna Mures | 960.66 mi (1,546.03 km) |
| Mariehamn to Odobesti | 1,032.50 mi (1,661.64 km) |
| Mariehamn to Odorheiu Secuiesc | 977.30 mi (1,572.81 km) |
| Mariehamn to Oltenita | 1,141.01 mi (1,836.28 km) |
| Mariehamn to Onesti | 996.08 mi (1,603.04 km) |
| Mariehamn to Oradea | 903.71 mi (1,454.39 km) |
| Mariehamn to Orastie | 993.61 mi (1,599.06 km) |
| Mariehamn to Oravita | 1,043.03 mi (1,678.60 km) |
| Mariehamn to Orsova | 1,067.16 mi (1,717.43 km) |
| Mariehamn to Otelu Rosu | 1,012.36 mi (1,629.24 km) |
| Mariehamn to Otopeni | 1,104.06 mi (1,776.82 km) |
| Mariehamn to Ovidiu | 1,150.90 mi (1,852.19 km) |
