| South Portland to Bonham (Texas) | 1,552.19 mi (2,498.00 km) |
| South Portland to Bonita (California) | 2,612.78 mi (4,204.86 km) |
| South Portland to Bonita Springs (Florida) | 1,356.35 mi (2,182.84 km) |
| South Portland to Bonney Lake (Washington) | 2,482.03 mi (3,994.44 km) |
| South Portland to Boone (Iowa) | 1,195.89 mi (1,924.59 km) |
| South Portland to Boone (North Carolina) | 790.08 mi (1,271.51 km) |
| South Portland to Borger (Texas) | 1,732.56 mi (2,788.28 km) |
| South Portland to Bossier City (Louisiana) | 1,477.40 mi (2,377.65 km) |
| South Portland to Boston (Massachusetts) | 99.19 mi (159.62 km) |
| South Portland to Bostonia (California) | 2,603.28 mi (4,189.58 km) |
| South Portland to Bothell (Washington) | 2,473.98 mi (3,981.48 km) |
| South Portland to Bothell East (Washington) | 2,472.56 mi (3,979.19 km) |
| South Portland to Bothell West (Washington) | 2,475.09 mi (3,983.26 km) |
| South Portland to Boulder (Colorado) | 1,803.68 mi (2,902.75 km) |
| South Portland to Boulder City (Nevada) | 2,401.72 mi (3,865.19 km) |
