| Thornbury to Ickenham | 89.22 mi (143.58 km) |
| Thornbury to Ifield | 105.46 mi (169.72 km) |
| Thornbury to Ilford | 112.14 mi (180.47 km) |
| Thornbury to Ilfracombe | 74.13 mi (119.30 km) |
| Thornbury to Ilkeston | 107.19 mi (172.51 km) |
| Thornbury to Ilkley | 162.67 mi (261.79 km) |
| Thornbury to Immingham | 168.94 mi (271.88 km) |
| Thornbury to Ince-in-Makerfield | 133.44 mi (214.75 km) |
| Thornbury to Inverness | 411.12 mi (661.63 km) |
| Thornbury to Inverurie | 391.84 mi (630.61 km) |
| Thornbury to Ipswich | 160.17 mi (257.76 km) |
| Thornbury to Irlam | 126.90 mi (204.23 km) |
| Thornbury to Irthlingborough | 95.15 mi (153.13 km) |
| Thornbury to Irvine | 290.58 mi (467.65 km) |
| Thornbury to Islington | 104.10 mi (167.53 km) |
