| Holyhead to McKeesport (Pennsylvania) | 3,493.02 mi (5,621.47 km) |
| Holyhead to McKinleyville (California) | 4,997.11 mi (8,042.08 km) |
| Holyhead to McKinney (Texas) | 4,496.61 mi (7,236.60 km) |
| Holyhead to McLean (Virginia) | 3,452.08 mi (5,555.59 km) |
| Holyhead to McMinnville (Oregon) | 4,727.12 mi (7,607.56 km) |
| Holyhead to McMinnville (Tennessee) | 3,948.66 mi (6,354.75 km) |
| Holyhead to McNair (Virginia) | 3,460.42 mi (5,569.00 km) |
| Holyhead to McPherson (Kansas) | 4,267.84 mi (6,868.42 km) |
| Holyhead to Mead Valley (California) | 5,196.36 mi (8,362.73 km) |
| Holyhead to Meadow Woods (Florida) | 4,137.18 mi (6,658.15 km) |
| Holyhead to Meadowbrook (Virginia) | 3,533.78 mi (5,687.07 km) |
| Holyhead to Meadville (Pennsylvania) | 3,445.47 mi (5,544.95 km) |
| Holyhead to Mebane (North Carolina) | 3,670.00 mi (5,906.29 km) |
| Holyhead to Mechanicsville (Virginia) | 3,519.83 mi (5,664.62 km) |
| Holyhead to Medford (Massachusetts) | 3,053.48 mi (4,914.10 km) |
