| Merthyr Tudful to Mancha Real | 964.37 mi (1,552.01 km) |
| Merthyr Tudful to Manilva | 1,065.22 mi (1,714.31 km) |
| Merthyr Tudful to Manises | 858.62 mi (1,381.81 km) |
| Merthyr Tudful to Manlleu | 723.80 mi (1,164.84 km) |
| Merthyr Tudful to Manresa | 734.22 mi (1,181.61 km) |
| Merthyr Tudful to Manzanares | 880.70 mi (1,417.36 km) |
| Merthyr Tudful to Manzanares el Real | 761.46 mi (1,225.46 km) |
| Merthyr Tudful to Maracena | 1,004.90 mi (1,617.23 km) |
| Merthyr Tudful to Marbella | 1,054.62 mi (1,697.25 km) |
| Merthyr Tudful to Marchena | 1,000.56 mi (1,610.24 km) |
| Merthyr Tudful to Marin | 692.39 mi (1,114.29 km) |
| Merthyr Tudful to Marratxi | 886.11 mi (1,426.06 km) |
| Merthyr Tudful to Martorell | 752.40 mi (1,210.87 km) |
| Merthyr Tudful to Martos | 969.55 mi (1,560.33 km) |
| Merthyr Tudful to Masamagrell | 853.64 mi (1,373.79 km) |
