| South Portland to Ickenham | 3,173.52 mi (5,107.29 km) |
| South Portland to Ifield | 3,193.24 mi (5,139.03 km) |
| South Portland to Ilford | 3,195.21 mi (5,142.20 km) |
| South Portland to Ilfracombe | 3,030.50 mi (4,877.12 km) |
| South Portland to Ilkeston | 3,108.66 mi (5,002.90 km) |
| South Portland to Ilkley | 3,069.69 mi (4,940.19 km) |
| South Portland to Immingham | 3,138.59 mi (5,051.07 km) |
| South Portland to Ince-in-Makerfield | 3,046.38 mi (4,902.68 km) |
| South Portland to Inverness | 2,922.37 mi (4,703.10 km) |
| South Portland to Inverurie | 2,992.42 mi (4,815.84 km) |
| South Portland to Ipswich | 3,226.82 mi (5,193.06 km) |
| South Portland to Irlam | 3,055.18 mi (4,916.84 km) |
| South Portland to Irthlingborough | 3,149.98 mi (5,069.40 km) |
| South Portland to Irvine | 2,931.45 mi (4,717.71 km) |
| South Portland to Islington | 3,187.87 mi (5,130.39 km) |
