| Key West to Mauldin (South Carolina) | 706.69 mi (1,137.31 km) |
| Key West to Maumee (Ohio) | 1,179.94 mi (1,898.93 km) |
| Key West to Maumelle (Arkansas) | 953.52 mi (1,534.55 km) |
| Key West to Mayagüez (Puerto Rico) | 1,038.40 mi (1,671.14 km) |
| Key West to Mayfield Heights (Ohio) | 1,171.50 mi (1,885.35 km) |
| Key West to Mays Chapel (Maryland) | 1,069.90 mi (1,721.84 km) |
| Key West to Maywood (California) | 2,275.56 mi (3,662.16 km) |
| Key West to Maywood (Illinois) | 1,245.84 mi (2,004.99 km) |
| Key West to McAlester (Oklahoma) | 1,101.27 mi (1,772.32 km) |
| Key West to McAllen (Texas) | 1,033.64 mi (1,663.48 km) |
| Key West to McCalla (Alabama) | 681.91 mi (1,097.43 km) |
| Key West to McComb (Mississippi) | 702.94 mi (1,131.28 km) |
| Key West to McDonough (Georgia) | 629.72 mi (1,013.43 km) |
| Key West to McFarland (California) | 2,350.42 mi (3,782.63 km) |
| Key West to McHenry (Illinois) | 1,283.22 mi (2,065.14 km) |
