| Helmstedt to Obernburg am Main | 183.89 mi (295.94 km) |
| Helmstedt to Obernkirchen | 80.11 mi (128.93 km) |
| Helmstedt to Oberschleissheim | 275.95 mi (444.11 km) |
| Helmstedt to Oberstdorf | 334.51 mi (538.34 km) |
| Helmstedt to Obertraubling | 231.03 mi (371.81 km) |
| Helmstedt to Obertshausen | 176.64 mi (284.27 km) |
| Helmstedt to Oberursel | 175.10 mi (281.79 km) |
| Helmstedt to Ochsenfurt | 182.80 mi (294.20 km) |
| Helmstedt to Ochsenhausen | 290.96 mi (468.26 km) |
| Helmstedt to Ochtrup | 161.71 mi (260.24 km) |
| Helmstedt to Odenthal | 186.26 mi (299.75 km) |
| Helmstedt to Oelde | 124.61 mi (200.55 km) |
| Helmstedt to Oelsnitz | 134.74 mi (216.84 km) |
| Helmstedt to Oer-Erkenschwick | 165.18 mi (265.83 km) |
| Helmstedt to Oerlinghausen | 101.11 mi (162.72 km) |
