| SeaTac to Mangualde | 5,151.81 mi (8,291.03 km) |
| SeaTac to Marco de Canavezes | 5,108.07 mi (8,220.64 km) |
| SeaTac to Marinha Grande | 5,157.43 mi (8,300.09 km) |
| SeaTac to Massama | 5,198.18 mi (8,365.67 km) |
| SeaTac to Matosinhos | 5,089.65 mi (8,190.99 km) |
| SeaTac to Mealhada | 5,140.35 mi (8,272.60 km) |
| SeaTac to Melgaco | 5,054.84 mi (8,134.97 km) |
| SeaTac to Melres | 5,105.87 mi (8,217.11 km) |
| SeaTac to Mira | 5,128.12 mi (8,252.92 km) |
| SeaTac to Miranda do Corvo | 5,159.32 mi (8,303.12 km) |
| SeaTac to Mirandela | 5,124.14 mi (8,246.51 km) |
| SeaTac to Mogadouro | 5,147.55 mi (8,284.18 km) |
| SeaTac to Moimenta da Beira | 5,136.76 mi (8,266.81 km) |
| SeaTac to Moita | 5,213.94 mi (8,391.02 km) |
| SeaTac to Moncao | 5,050.06 mi (8,127.29 km) |
