| Olbia to Montemor-o-Novo | 951.93 mi (1,531.98 km) |
| Olbia to Montemor-o-Velho | 954.42 mi (1,535.99 km) |
| Olbia to Montijo | 986.95 mi (1,588.34 km) |
| Olbia to Mortagua | 928.26 mi (1,493.90 km) |
| Olbia to Moura | 922.02 mi (1,483.84 km) |
| Olbia to Murtosa | 946.46 mi (1,523.18 km) |
| Olbia to Nazare | 981.34 mi (1,579.31 km) |
| Olbia to Nelas | 907.53 mi (1,460.53 km) |
| Olbia to Obidos | 989.50 mi (1,592.45 km) |
| Olbia to Odemira | 995.20 mi (1,601.63 km) |
| Olbia to Odivelas | 999.67 mi (1,608.82 km) |
| Olbia to Oeiras | 1,008.68 mi (1,623.31 km) |
| Olbia to Olhao | 967.66 mi (1,557.29 km) |
| Olbia to Oliveira de Azemeis | 937.40 mi (1,508.60 km) |
| Olbia to Oliveira de Frades | 923.19 mi (1,485.73 km) |
