| Merthyr Tudful to Manassas (Virginia) | 3,552.16 mi (5,716.64 km) |
| Merthyr Tudful to Manassas Park (Virginia) | 3,549.45 mi (5,712.29 km) |
| Merthyr Tudful to Manatí (Puerto Rico) | 4,081.45 mi (6,568.46 km) |
| Merthyr Tudful to Manchester (Missouri) | 4,081.47 mi (6,568.49 km) |
| Merthyr Tudful to Manchester (New Hampshire) | 3,123.36 mi (5,026.56 km) |
| Merthyr Tudful to Manchester (Tennessee) | 4,055.10 mi (6,526.05 km) |
| Merthyr Tudful to Manchester (Virginia) | 3,611.18 mi (5,811.63 km) |
| Merthyr Tudful to Mandan (North Dakota) | 4,065.93 mi (6,543.48 km) |
| Merthyr Tudful to Mandeville (Louisiana) | 4,468.84 mi (7,191.91 km) |
| Merthyr Tudful to Mango (Florida) | 4,265.54 mi (6,864.73 km) |
| Merthyr Tudful to Manhattan (Kansas) | 4,285.18 mi (6,896.33 km) |
| Merthyr Tudful to Manhattan (New York) | 3,318.55 mi (5,340.68 km) |
| Merthyr Tudful to Manhattan Beach (California) | 5,338.40 mi (8,591.32 km) |
| Merthyr Tudful to Manitowoc (Wisconsin) | 3,717.30 mi (5,982.41 km) |
| Merthyr Tudful to Mankato (Minnesota) | 3,948.32 mi (6,354.21 km) |
