| Holyhead to Mauldin (South Carolina) | 3,854.73 mi (6,203.59 km) |
| Holyhead to Maumee (Ohio) | 3,585.49 mi (5,770.30 km) |
| Holyhead to Maumelle (Arkansas) | 4,248.41 mi (6,837.16 km) |
| Holyhead to Mayagüez (Puerto Rico) | 4,088.27 mi (6,579.43 km) |
| Holyhead to Mayfield Heights (Ohio) | 3,502.31 mi (5,636.42 km) |
| Holyhead to Mays Chapel (Maryland) | 3,407.83 mi (5,484.38 km) |
| Holyhead to Maywood (California) | 5,216.92 mi (8,395.83 km) |
| Holyhead to Maywood (Illinois) | 3,730.52 mi (6,003.69 km) |
| Holyhead to McAlester (Oklahoma) | 4,373.55 mi (7,038.55 km) |
| Holyhead to McAllen (Texas) | 4,926.56 mi (7,928.53 km) |
| Holyhead to McCalla (Alabama) | 4,116.55 mi (6,624.94 km) |
| Holyhead to McComb (Mississippi) | 4,357.33 mi (7,012.44 km) |
| Holyhead to McDonough (Georgia) | 3,994.94 mi (6,429.23 km) |
| Holyhead to McFarland (California) | 5,154.31 mi (8,295.06 km) |
| Holyhead to McHenry (Illinois) | 3,725.88 mi (5,996.23 km) |
