| South Portland to Norwich | 3,219.31 mi (5,180.98 km) |
| South Portland to Nottingham | 3,115.34 mi (5,013.66 km) |
| South Portland to Nuneaton | 3,111.51 mi (5,007.50 km) |
| South Portland to Oadby | 3,125.62 mi (5,030.21 km) |
| South Portland to Oakengates | 3,068.60 mi (4,938.43 km) |
| South Portland to Oakham | 3,137.82 mi (5,049.83 km) |
| South Portland to Oldbury | 3,089.89 mi (4,972.69 km) |
| South Portland to Oldham | 3,065.34 mi (4,933.19 km) |
| South Portland to Ollerton | 3,115.47 mi (5,013.86 km) |
| South Portland to Olton | 3,099.71 mi (4,988.50 km) |
| South Portland to Omagh | 2,844.46 mi (4,577.72 km) |
| South Portland to Ormesby | 3,082.84 mi (4,961.34 km) |
| South Portland to Ormskirk | 3,034.51 mi (4,883.58 km) |
| South Portland to Orpington | 3,199.94 mi (5,149.80 km) |
| South Portland to Ossett | 3,083.87 mi (4,963.00 km) |
