| Willoughby to Mattoon (Illinois) | 394.42 mi (634.75 km) |
| Willoughby to Mauldin (South Carolina) | 476.72 mi (767.20 km) |
| Willoughby to Maumee (Ohio) | 116.62 mi (187.69 km) |
| Willoughby to Maumelle (Arkansas) | 757.91 mi (1,219.74 km) |
| Willoughby to Mayagüez (Puerto Rico) | 1,825.60 mi (2,938.02 km) |
| Willoughby to Mayfield Heights (Ohio) | 9.18 mi (14.77 km) |
| Willoughby to Mays Chapel (Maryland) | 292.74 mi (471.11 km) |
| Willoughby to Maywood (California) | 2,059.10 mi (3,313.79 km) |
| Willoughby to Maywood (Illinois) | 332.00 mi (534.30 km) |
| Willoughby to McAlester (Oklahoma) | 905.16 mi (1,456.71 km) |
| Willoughby to McAllen (Texas) | 1,432.30 mi (2,305.07 km) |
| Willoughby to McCalla (Alabama) | 653.36 mi (1,051.47 km) |
| Willoughby to McComb (Mississippi) | 876.49 mi (1,410.58 km) |
| Willoughby to McDonough (Georgia) | 586.46 mi (943.82 km) |
| Willoughby to McFarland (California) | 2,065.16 mi (3,323.55 km) |
