| Hertford to Oberkirch | 425.42 mi (684.64 km) |
| Hertford to Obernburg am Main | 424.17 mi (682.63 km) |
| Hertford to Obernkirchen | 391.95 mi (630.78 km) |
| Hertford to Oberschleissheim | 571.17 mi (919.21 km) |
| Hertford to Oberstdorf | 553.22 mi (890.32 km) |
| Hertford to Obertraubling | 572.98 mi (922.13 km) |
| Hertford to Obertshausen | 405.71 mi (652.93 km) |
| Hertford to Oberursel | 391.80 mi (630.55 km) |
| Hertford to Ochsenfurt | 467.38 mi (752.17 km) |
| Hertford to Ochsenhausen | 514.15 mi (827.44 km) |
| Hertford to Ochtrup | 310.30 mi (499.38 km) |
| Hertford to Odenthal | 314.33 mi (505.86 km) |
| Hertford to Oelde | 351.25 mi (565.27 km) |
| Hertford to Oelsnitz | 538.99 mi (867.41 km) |
| Hertford to Oer-Erkenschwick | 313.73 mi (504.89 km) |
