| South Portland to Buena Park (California) | 2,620.28 mi (4,216.94 km) |
| South Portland to Buenaventura Lakes (Florida) | 1,222.01 mi (1,966.64 km) |
| South Portland to Buffalo (Minnesota) | 1,164.42 mi (1,873.95 km) |
| South Portland to Buffalo (New York) | 433.37 mi (697.44 km) |
| South Portland to Buffalo Grove (Illinois) | 898.43 mi (1,445.88 km) |
| South Portland to Buford (Georgia) | 985.05 mi (1,585.29 km) |
| South Portland to Bull Run (Virginia) | 503.25 mi (809.90 km) |
| South Portland to Bullhead City (Arizona) | 2,405.59 mi (3,871.42 km) |
| South Portland to Burbank (California) | 2,625.07 mi (4,224.64 km) |
| South Portland to Burbank (Illinois) | 895.53 mi (1,441.22 km) |
| South Portland to Burien (Washington) | 2,484.85 mi (3,998.98 km) |
| South Portland to Burkburnett (Texas) | 1,648.18 mi (2,652.49 km) |
| South Portland to Burke (Virginia) | 493.52 mi (794.24 km) |
| South Portland to Burke Centre (Virginia) | 494.28 mi (795.46 km) |
| South Portland to Burleson (Texas) | 1,648.86 mi (2,653.59 km) |
