| Merthyr Tudful to Mineral Wells (Texas) | 4,662.73 mi (7,503.95 km) |
| Merthyr Tudful to Minneapolis (Minnesota) | 3,885.70 mi (6,253.43 km) |
| Merthyr Tudful to Minnehaha (Washington) | 4,802.14 mi (7,728.29 km) |
| Merthyr Tudful to Minneola (Florida) | 4,210.65 mi (6,776.39 km) |
| Merthyr Tudful to Minnetonka (Minnesota) | 3,894.13 mi (6,267.00 km) |
| Merthyr Tudful to Minooka (Illinois) | 3,860.32 mi (6,212.58 km) |
| Merthyr Tudful to Minot (North Dakota) | 4,011.53 mi (6,455.93 km) |
| Merthyr Tudful to Mint Hill (North Carolina) | 3,846.81 mi (6,190.85 km) |
| Merthyr Tudful to Miramar (Florida) | 4,283.35 mi (6,893.39 km) |
| Merthyr Tudful to Mishawaka (Indiana) | 3,768.23 mi (6,064.37 km) |
| Merthyr Tudful to Mission (Texas) | 5,017.08 mi (8,074.21 km) |
| Merthyr Tudful to Mission Bend (Texas) | 4,728.55 mi (7,609.87 km) |
| Merthyr Tudful to Mission Viejo (California) | 5,329.60 mi (8,577.16 km) |
| Merthyr Tudful to Missoula (Montana) | 4,485.48 mi (7,218.69 km) |
| Merthyr Tudful to Missouri City (Texas) | 4,730.18 mi (7,612.50 km) |
