| Staines-upon-Thames to Mangualde | 824.20 mi (1,326.42 km) |
| Staines-upon-Thames to Marco de Canavezes | 795.57 mi (1,280.34 km) |
| Staines-upon-Thames to Marinha Grande | 902.77 mi (1,452.87 km) |
| Staines-upon-Thames to Massama | 973.01 mi (1,565.91 km) |
| Staines-upon-Thames to Matosinhos | 807.77 mi (1,299.98 km) |
| Staines-upon-Thames to Mealhada | 852.43 mi (1,371.85 km) |
| Staines-upon-Thames to Melgaco | 740.07 mi (1,191.02 km) |
| Staines-upon-Thames to Melres | 808.33 mi (1,300.88 km) |
| Staines-upon-Thames to Mira | 855.38 mi (1,376.60 km) |
| Staines-upon-Thames to Miranda do Corvo | 867.95 mi (1,396.84 km) |
| Staines-upon-Thames to Mirandela | 756.41 mi (1,217.32 km) |
| Staines-upon-Thames to Mogadouro | 757.31 mi (1,218.77 km) |
| Staines-upon-Thames to Moimenta da Beira | 797.28 mi (1,283.09 km) |
| Staines-upon-Thames to Moita | 973.79 mi (1,567.17 km) |
| Staines-upon-Thames to Moncao | 747.73 mi (1,203.35 km) |
