| Santander to Mangualde | 283.18 mi (455.74 km) |
| Santander to Marco de Canavezes | 272.10 mi (437.91 km) |
| Santander to Marinha Grande | 368.64 mi (593.27 km) |
| Santander to Massama | 432.01 mi (695.25 km) |
| Santander to Matosinhos | 295.45 mi (475.48 km) |
| Santander to Mealhada | 319.74 mi (514.57 km) |
| Santander to Melgaco | 244.56 mi (393.58 km) |
| Santander to Melres | 287.35 mi (462.44 km) |
| Santander to Mira | 328.46 mi (528.60 km) |
| Santander to Miranda do Corvo | 329.17 mi (529.75 km) |
| Santander to Mirandela | 219.70 mi (353.57 km) |
| Santander to Mogadouro | 209.07 mi (336.46 km) |
| Santander to Moimenta da Beira | 259.59 mi (417.76 km) |
| Santander to Moita | 428.02 mi (688.84 km) |
| Santander to Moncao | 255.78 mi (411.63 km) |
