| Grevena to Oberkirch | 878.64 mi (1,414.03 km) |
| Grevena to Obernburg am Main | 900.49 mi (1,449.20 km) |
| Grevena to Obernkirchen | 1,024.19 mi (1,648.27 km) |
| Grevena to Oberschleissheim | 745.16 mi (1,199.22 km) |
| Grevena to Oberstdorf | 750.80 mi (1,208.30 km) |
| Grevena to Obertraubling | 763.38 mi (1,228.54 km) |
| Grevena to Obertshausen | 921.22 mi (1,482.55 km) |
| Grevena to Oberursel | 935.95 mi (1,506.26 km) |
| Grevena to Ochsenfurt | 861.91 mi (1,387.12 km) |
| Grevena to Ochsenhausen | 791.63 mi (1,274.00 km) |
| Grevena to Ochtrup | 1,075.73 mi (1,731.22 km) |
| Grevena to Odenthal | 1,021.88 mi (1,644.55 km) |
| Grevena to Oelde | 1,028.91 mi (1,655.88 km) |
| Grevena to Oelsnitz | 842.64 mi (1,356.10 km) |
| Grevena to Oer-Erkenschwick | 1,046.45 mi (1,684.10 km) |
