| Halden to Oerlinghausen | 506.67 mi (815.41 km) |
| Halden to Oestrich-Winkel | 645.60 mi (1,038.99 km) |
| Halden to Offenburg | 750.35 mi (1,207.58 km) |
| Halden to Oftersheim | 683.97 mi (1,100.75 km) |
| Halden to Ohrdruf | 574.12 mi (923.95 km) |
| Halden to Ohringen | 690.44 mi (1,111.16 km) |
| Halden to Olbernhau | 589.06 mi (947.99 km) |
| Halden to Olching | 754.97 mi (1,215.01 km) |
| Halden to Oldenburg | 431.96 mi (695.16 km) |
| Halden to Oldenburg in Holstein | 334.24 mi (537.91 km) |
| Halden to Olfen | 536.35 mi (863.18 km) |
| Halden to Olpe | 578.41 mi (930.86 km) |
| Halden to Olsberg | 549.99 mi (885.13 km) |
| Halden to Oranienburg | 445.42 mi (716.84 km) |
| Halden to Ortenberg | 613.57 mi (987.45 km) |
