| Didcot to Ifield | 55.68 mi (89.61 km) |
| Didcot to Ilford | 57.06 mi (91.83 km) |
| Didcot to Ilfracombe | 127.08 mi (204.52 km) |
| Didcot to Ilkeston | 94.36 mi (151.85 km) |
| Didcot to Ilkley | 162.06 mi (260.80 km) |
| Didcot to Immingham | 145.21 mi (233.70 km) |
| Didcot to Ince-in-Makerfield | 145.29 mi (233.82 km) |
| Didcot to Inverness | 422.86 mi (680.52 km) |
| Didcot to Inverurie | 394.68 mi (635.18 km) |
| Didcot to Ipswich | 107.01 mi (172.21 km) |
| Didcot to Irlam | 136.41 mi (219.53 km) |
| Didcot to Irthlingborough | 56.33 mi (90.66 km) |
| Didcot to Irvine | 310.68 mi (499.99 km) |
| Didcot to Islington | 49.07 mi (78.96 km) |
| Didcot to Iver | 32.07 mi (51.61 km) |
