| Willoughby to McHenry (Illinois) | 356.68 mi (574.01 km) |
| Willoughby to McKeesport (Pennsylvania) | 121.55 mi (195.61 km) |
| Willoughby to McKinleyville (California) | 2,192.89 mi (3,529.11 km) |
| Willoughby to McKinney (Texas) | 1,018.02 mi (1,638.35 km) |
| Willoughby to McLean (Virginia) | 290.07 mi (466.83 km) |
| Willoughby to McMinnville (Oregon) | 2,087.42 mi (3,359.38 km) |
| Willoughby to McMinnville (Tennessee) | 474.38 mi (763.45 km) |
| Willoughby to McNair (Virginia) | 281.05 mi (452.31 km) |
| Willoughby to McPherson (Kansas) | 887.84 mi (1,428.84 km) |
| Willoughby to Mead Valley (California) | 2,017.27 mi (3,246.48 km) |
| Willoughby to Meadow Woods (Florida) | 917.30 mi (1,476.25 km) |
| Willoughby to Meadowbrook (Virginia) | 358.79 mi (577.41 km) |
| Willoughby to Meadville (Pennsylvania) | 65.14 mi (104.83 km) |
| Willoughby to Mebane (North Carolina) | 400.97 mi (645.29 km) |
| Willoughby to Mechanicsville (Virginia) | 351.51 mi (565.70 km) |
