| Watford to Illzach | 436.95 mi (703.21 km) |
| Watford to Ingre | 276.34 mi (444.72 km) |
| Watford to Irigny | 476.71 mi (767.20 km) |
| Watford to Isbergues | 142.72 mi (229.68 km) |
| Watford to Issoire | 453.72 mi (730.20 km) |
| Watford to Issoudun | 342.51 mi (551.22 km) |
| Watford to Issy-les-Moulineaux | 228.31 mi (367.42 km) |
| Watford to Istres | 615.45 mi (990.47 km) |
| Watford to Ivry-sur-Seine | 231.68 mi (372.85 km) |
| Watford to Jarville-la-Malgrange | 357.47 mi (575.29 km) |
| Watford to Jeumont | 217.01 mi (349.25 km) |
| Watford to Joigny | 304.84 mi (490.60 km) |
| Watford to Joinville-le-Pont | 233.20 mi (375.29 km) |
| Watford to Joue-les-Tours | 301.11 mi (484.59 km) |
| Watford to Jouy-le-Moutier | 211.88 mi (340.99 km) |
