| Southborough to Mauldin (South Carolina) | 4,095.35 mi (6,590.83 km) |
| Southborough to Maumee (Ohio) | 3,834.48 mi (6,171.01 km) |
| Southborough to Maumelle (Arkansas) | 4,497.35 mi (7,237.79 km) |
| Southborough to Mayagüez (Puerto Rico) | 4,271.60 mi (6,874.47 km) |
| Southborough to Mayfield Heights (Ohio) | 3,749.89 mi (6,034.86 km) |
| Southborough to Mays Chapel (Maryland) | 3,649.13 mi (5,872.70 km) |
| Southborough to Maywood (California) | 5,470.99 mi (8,804.71 km) |
| Southborough to Maywood (Illinois) | 3,981.90 mi (6,408.24 km) |
| Southborough to McAlester (Oklahoma) | 4,624.49 mi (7,442.40 km) |
| Southborough to McAllen (Texas) | 5,173.37 mi (8,325.74 km) |
| Southborough to McCalla (Alabama) | 4,359.97 mi (7,016.70 km) |
| Southborough to McComb (Mississippi) | 4,601.78 mi (7,405.85 km) |
| Southborough to McDonough (Georgia) | 4,235.77 mi (6,816.82 km) |
| Southborough to McFarland (California) | 5,407.66 mi (8,702.79 km) |
| Southborough to McHenry (Illinois) | 3,977.74 mi (6,401.56 km) |
