| Slough to Ickenham | 6.91 mi (11.13 km) |
| Slough to Ifield | 31.27 mi (50.33 km) |
| Slough to Ilford | 29.16 mi (46.93 km) |
| Slough to Ilfracombe | 153.78 mi (247.48 km) |
| Slough to Ilkeston | 105.56 mi (169.88 km) |
| Slough to Ilkley | 174.77 mi (281.26 km) |
| Slough to Immingham | 146.30 mi (235.45 km) |
| Slough to Ince-in-Makerfield | 163.86 mi (263.70 km) |
| Slough to Inverness | 437.35 mi (703.84 km) |
| Slough to Inverurie | 405.20 mi (652.11 km) |
| Slough to Ipswich | 83.69 mi (134.68 km) |
| Slough to Irlam | 154.46 mi (248.57 km) |
| Slough to Irthlingborough | 56.36 mi (90.71 km) |
| Slough to Irvine | 329.49 mi (530.26 km) |
| Slough to Islington | 21.01 mi (33.81 km) |
