| Holyhead to Mangualde | 889.90 mi (1,432.16 km) |
| Holyhead to Marco de Canavezes | 853.62 mi (1,373.77 km) |
| Holyhead to Marinha Grande | 958.43 mi (1,542.44 km) |
| Holyhead to Massama | 1,029.26 mi (1,656.44 km) |
| Holyhead to Matosinhos | 858.88 mi (1,382.24 km) |
| Holyhead to Mealhada | 910.77 mi (1,465.75 km) |
| Holyhead to Melgaco | 791.28 mi (1,273.44 km) |
| Holyhead to Melres | 863.84 mi (1,390.22 km) |
| Holyhead to Mira | 910.07 mi (1,464.62 km) |
| Holyhead to Miranda do Corvo | 929.02 mi (1,495.11 km) |
| Holyhead to Mirandela | 825.45 mi (1,328.43 km) |
| Holyhead to Mogadouro | 833.08 mi (1,340.72 km) |
| Holyhead to Moimenta da Beira | 863.11 mi (1,389.04 km) |
| Holyhead to Moita | 1,033.66 mi (1,663.52 km) |
| Holyhead to Moncao | 796.36 mi (1,281.62 km) |
