| Harpenden to Illzach | 441.95 mi (711.24 km) |
| Harpenden to Ingre | 286.13 mi (460.48 km) |
| Harpenden to Irigny | 485.32 mi (781.05 km) |
| Harpenden to Isbergues | 146.90 mi (236.42 km) |
| Harpenden to Issoire | 463.39 mi (745.75 km) |
| Harpenden to Issoudun | 352.55 mi (567.37 km) |
| Harpenden to Issy-les-Moulineaux | 236.96 mi (381.34 km) |
| Harpenden to Istres | 624.76 mi (1,005.45 km) |
| Harpenden to Ivry-sur-Seine | 240.21 mi (386.59 km) |
| Harpenden to Jarville-la-Malgrange | 362.12 mi (582.77 km) |
| Harpenden to Jeumont | 220.15 mi (354.29 km) |
| Harpenden to Joigny | 313.06 mi (503.83 km) |
| Harpenden to Joinville-le-Pont | 241.59 mi (388.81 km) |
| Harpenden to Joue-les-Tours | 311.90 mi (501.95 km) |
| Harpenden to Jouy-le-Moutier | 220.63 mi (355.06 km) |
