| South Portland to Bound Brook (New Jersey) | 303.64 mi (488.66 km) |
| South Portland to Bountiful (Utah) | 2,112.53 mi (3,399.79 km) |
| South Portland to Bourbonnais (Illinois) | 911.31 mi (1,466.61 km) |
| South Portland to Bowie (Maryland) | 465.06 mi (748.44 km) |
| South Portland to Bowling Green (Kentucky) | 964.98 mi (1,552.99 km) |
| South Portland to Bowling Green (Ohio) | 697.27 mi (1,122.15 km) |
| South Portland to Box Elder (South Dakota) | 1,622.81 mi (2,611.65 km) |
| South Portland to Boynton Beach (Florida) | 1,302.69 mi (2,096.48 km) |
| South Portland to Bozeman (Montana) | 1,986.86 mi (3,197.55 km) |
| South Portland to Bradenton (Florida) | 1,308.43 mi (2,105.71 km) |
| South Portland to Bradfordville (Florida) | 1,180.68 mi (1,900.13 km) |
| South Portland to Bradley (Illinois) | 910.03 mi (1,464.55 km) |
| South Portland to Bradley Gardens (New Jersey) | 308.26 mi (496.10 km) |
| South Portland to Brainerd (Minnesota) | 1,178.65 mi (1,896.86 km) |
| South Portland to Brambleton (Virginia) | 494.20 mi (795.34 km) |
