| Stockton-on-Tees to Mangualde | 1,009.51 mi (1,624.64 km) |
| Stockton-on-Tees to Marco de Canavezes | 976.46 mi (1,571.47 km) |
| Stockton-on-Tees to Marinha Grande | 1,083.10 mi (1,743.09 km) |
| Stockton-on-Tees to Massama | 1,154.10 mi (1,857.34 km) |
| Stockton-on-Tees to Matosinhos | 984.83 mi (1,584.93 km) |
| Stockton-on-Tees to Mealhada | 1,033.92 mi (1,663.94 km) |
| Stockton-on-Tees to Melgaco | 916.59 mi (1,475.11 km) |
| Stockton-on-Tees to Melres | 987.90 mi (1,589.88 km) |
| Stockton-on-Tees to Mira | 1,034.84 mi (1,665.42 km) |
| Stockton-on-Tees to Miranda do Corvo | 1,051.06 mi (1,691.52 km) |
| Stockton-on-Tees to Mirandela | 942.95 mi (1,517.53 km) |
| Stockton-on-Tees to Mogadouro | 947.35 mi (1,524.61 km) |
| Stockton-on-Tees to Moimenta da Beira | 982.45 mi (1,581.10 km) |
| Stockton-on-Tees to Moita | 1,156.89 mi (1,861.83 km) |
| Stockton-on-Tees to Moncao | 922.82 mi (1,485.14 km) |
