| Onex to Mangualde | 793.96 mi (1,277.75 km) |
| Onex to Marco de Canavezes | 789.85 mi (1,271.14 km) |
| Onex to Marinha Grande | 878.38 mi (1,413.62 km) |
| Onex to Massama | 934.12 mi (1,503.33 km) |
| Onex to Matosinhos | 814.53 mi (1,310.85 km) |
| Onex to Mealhada | 832.55 mi (1,339.87 km) |
| Onex to Melgaco | 764.28 mi (1,229.99 km) |
| Onex to Melres | 805.15 mi (1,295.77 km) |
| Onex to Mira | 843.12 mi (1,356.87 km) |
| Onex to Miranda do Corvo | 838.47 mi (1,349.38 km) |
| Onex to Mirandela | 736.00 mi (1,184.47 km) |
| Onex to Mogadouro | 720.87 mi (1,160.12 km) |
| Onex to Moimenta da Beira | 773.37 mi (1,244.62 km) |
| Onex to Moita | 926.45 mi (1,490.98 km) |
| Onex to Moncao | 775.41 mi (1,247.90 km) |
