| Sint-Niklaas to Obernburg am Main | 238.35 mi (383.58 km) |
| Sint-Niklaas to Obernkirchen | 226.44 mi (364.42 km) |
| Sint-Niklaas to Oberschleissheim | 388.22 mi (624.77 km) |
| Sint-Niklaas to Oberstdorf | 379.36 mi (610.53 km) |
| Sint-Niklaas to Obertraubling | 387.13 mi (623.02 km) |
| Sint-Niklaas to Obertshausen | 219.57 mi (353.36 km) |
| Sint-Niklaas to Oberursel | 205.56 mi (330.82 km) |
| Sint-Niklaas to Ochsenfurt | 281.40 mi (452.87 km) |
| Sint-Niklaas to Ochsenhausen | 336.67 mi (541.81 km) |
| Sint-Niklaas to Ochtrup | 149.31 mi (240.30 km) |
| Sint-Niklaas to Odenthal | 129.76 mi (208.83 km) |
| Sint-Niklaas to Oelde | 178.77 mi (287.71 km) |
| Sint-Niklaas to Oelsnitz | 354.49 mi (570.50 km) |
| Sint-Niklaas to Oer-Erkenschwick | 138.32 mi (222.60 km) |
| Sint-Niklaas to Oerlinghausen | 202.36 mi (325.66 km) |
