| Southborough to McKeesport (Pennsylvania) | 3,738.18 mi (6,016.02 km) |
| Southborough to McKinleyville (California) | 5,245.89 mi (8,442.44 km) |
| Southborough to McKinney (Texas) | 4,747.02 mi (7,639.60 km) |
| Southborough to McLean (Virginia) | 3,693.20 mi (5,943.63 km) |
| Southborough to McMinnville (Oregon) | 4,973.94 mi (8,004.78 km) |
| Southborough to McMinnville (Tennessee) | 4,193.47 mi (6,748.74 km) |
| Southborough to McNair (Virginia) | 3,701.75 mi (5,957.38 km) |
| Southborough to McPherson (Kansas) | 4,521.20 mi (7,276.16 km) |
| Southborough to Mead Valley (California) | 5,450.66 mi (8,772.00 km) |
| Southborough to Meadow Woods (Florida) | 4,367.92 mi (7,029.49 km) |
| Southborough to Meadowbrook (Virginia) | 3,773.04 mi (6,072.12 km) |
| Southborough to Meadville (Pennsylvania) | 3,692.31 mi (5,942.20 km) |
| Southborough to Mebane (North Carolina) | 3,909.23 mi (6,291.31 km) |
| Southborough to Mechanicsville (Virginia) | 3,759.25 mi (6,049.93 km) |
| Southborough to Medford (Massachusetts) | 3,294.16 mi (5,301.44 km) |
