| Hertford to Noventa Vicentina | 694.71 mi (1,118.03 km) |
| Hertford to Novi di Modena | 692.65 mi (1,114.71 km) |
| Hertford to Novi Ligure | 633.51 mi (1,019.54 km) |
| Hertford to Nuoro | 910.83 mi (1,465.84 km) |
| Hertford to Occhiobello | 714.09 mi (1,149.22 km) |
| Hertford to Oderzo | 705.67 mi (1,135.67 km) |
| Hertford to Oggiono | 596.42 mi (959.84 km) |
| Hertford to Olbia | 877.91 mi (1,412.86 km) |
| Hertford to Oleggio | 583.25 mi (938.65 km) |
| Hertford to Olgiate Comasco | 584.08 mi (939.98 km) |
| Hertford to Olgiate Olona | 589.27 mi (948.33 km) |
| Hertford to Omegna | 561.51 mi (903.66 km) |
| Hertford to Opera | 612.89 mi (986.34 km) |
| Hertford to Oppeano | 681.84 mi (1,097.32 km) |
| Hertford to Orbassano | 584.17 mi (940.13 km) |
