| Kastoria to Oberkirch | 851.43 mi (1,370.24 km) |
| Kastoria to Obernburg am Main | 871.75 mi (1,402.95 km) |
| Kastoria to Obernkirchen | 994.25 mi (1,600.09 km) |
| Kastoria to Oberschleissheim | 716.45 mi (1,153.01 km) |
| Kastoria to Oberstdorf | 723.61 mi (1,164.53 km) |
| Kastoria to Obertraubling | 733.89 mi (1,181.09 km) |
| Kastoria to Obertshausen | 892.45 mi (1,436.26 km) |
| Kastoria to Oberursel | 907.19 mi (1,459.99 km) |
| Kastoria to Ochsenfurt | 832.92 mi (1,340.45 km) |
| Kastoria to Ochsenhausen | 763.93 mi (1,229.43 km) |
| Kastoria to Ochtrup | 1,046.34 mi (1,683.93 km) |
| Kastoria to Odenthal | 993.13 mi (1,598.29 km) |
| Kastoria to Oelde | 999.42 mi (1,608.41 km) |
| Kastoria to Oelsnitz | 812.49 mi (1,307.57 km) |
| Kastoria to Oer-Erkenschwick | 1,017.33 mi (1,637.23 km) |
