| Grez-Doiceau to Obernburg am Main | 205.52 mi (330.75 km) |
| Grez-Doiceau to Obernkirchen | 217.49 mi (350.02 km) |
| Grez-Doiceau to Oberschleissheim | 352.52 mi (567.33 km) |
| Grez-Doiceau to Oberstdorf | 341.16 mi (549.05 km) |
| Grez-Doiceau to Obertraubling | 354.17 mi (569.99 km) |
| Grez-Doiceau to Obertshausen | 187.75 mi (302.15 km) |
| Grez-Doiceau to Oberursel | 174.37 mi (280.61 km) |
| Grez-Doiceau to Ochsenfurt | 248.85 mi (400.48 km) |
| Grez-Doiceau to Ochsenhausen | 299.02 mi (481.22 km) |
| Grez-Doiceau to Ochtrup | 147.76 mi (237.79 km) |
| Grez-Doiceau to Odenthal | 107.36 mi (172.78 km) |
| Grez-Doiceau to Oelde | 167.32 mi (269.28 km) |
| Grez-Doiceau to Oelsnitz | 328.22 mi (528.22 km) |
| Grez-Doiceau to Oer-Erkenschwick | 127.06 mi (204.48 km) |
| Grez-Doiceau to Oerlinghausen | 191.18 mi (307.67 km) |
