| South Portland to Dover (New Hampshire) | 42.73 mi (68.77 km) |
| South Portland to Dover (New Jersey) | 289.16 mi (465.37 km) |
| South Portland to Dover (Ohio) | 611.96 mi (984.86 km) |
| South Portland to Downers Grove (Illinois) | 907.10 mi (1,459.84 km) |
| South Portland to Downey (California) | 2,623.87 mi (4,222.72 km) |
| South Portland to Dranesville (Virginia) | 487.09 mi (783.90 km) |
| South Portland to Draper (Utah) | 2,121.01 mi (3,413.44 km) |
| South Portland to Drexel Heights (Arizona) | 2,332.82 mi (3,754.30 km) |
| South Portland to Drexel Hill (Pennsylvania) | 362.40 mi (583.22 km) |
| South Portland to Duarte (California) | 2,607.33 mi (4,196.09 km) |
| South Portland to Dublin (California) | 2,691.11 mi (4,330.93 km) |
| South Portland to Dublin (Georgia) | 1,027.21 mi (1,653.13 km) |
| South Portland to Dublin (Ohio) | 703.82 mi (1,132.68 km) |
| South Portland to Dubuque (Iowa) | 1,030.97 mi (1,659.19 km) |
| South Portland to Duluth (Georgia) | 997.03 mi (1,604.57 km) |
