| Halden to Oberkirch | 744.68 mi (1,198.44 km) |
| Halden to Obernburg am Main | 648.37 mi (1,043.45 km) |
| Halden to Obernkirchen | 482.76 mi (776.93 km) |
| Halden to Oberschleissheim | 751.49 mi (1,209.41 km) |
| Halden to Oberstdorf | 811.04 mi (1,305.24 km) |
| Halden to Obertraubling | 702.57 mi (1,130.67 km) |
| Halden to Obertshausen | 634.76 mi (1,021.54 km) |
| Halden to Oberursel | 627.21 mi (1,009.40 km) |
| Halden to Ochsenfurt | 657.19 mi (1,057.65 km) |
| Halden to Ochsenhausen | 766.31 mi (1,233.25 km) |
| Halden to Ochtrup | 506.34 mi (814.87 km) |
| Halden to Odenthal | 584.92 mi (941.34 km) |
| Halden to Oelde | 520.36 mi (837.44 km) |
| Halden to Oelsnitz | 602.39 mi (969.45 km) |
| Halden to Oer-Erkenschwick | 542.86 mi (873.65 km) |
