| Gretna to Ickenham | 4,613.94 mi (7,425.43 km) |
| Gretna to Ifield | 4,633.81 mi (7,457.40 km) |
| Gretna to Ilford | 4,635.58 mi (7,460.24 km) |
| Gretna to Ilfracombe | 4,471.11 mi (7,195.55 km) |
| Gretna to Ilkeston | 4,548.02 mi (7,319.33 km) |
| Gretna to Ilkley | 4,507.75 mi (7,254.52 km) |
| Gretna to Immingham | 4,576.68 mi (7,365.45 km) |
| Gretna to Ince-in-Makerfield | 4,485.29 mi (7,218.38 km) |
| Gretna to Inverness | 4,351.24 mi (7,002.65 km) |
| Gretna to Inverurie | 4,421.17 mi (7,115.18 km) |
| Gretna to Ipswich | 4,666.62 mi (7,510.20 km) |
| Gretna to Irlam | 4,494.18 mi (7,232.69 km) |
| Gretna to Irthlingborough | 4,589.89 mi (7,386.71 km) |
| Gretna to Irvine | 4,366.72 mi (7,027.55 km) |
| Gretna to Islington | 4,628.27 mi (7,448.47 km) |
