| Potters Bar to Oberkirch | 426.18 mi (685.87 km) |
| Potters Bar to Obernburg am Main | 426.85 mi (686.95 km) |
| Potters Bar to Obernkirchen | 397.46 mi (639.65 km) |
| Potters Bar to Oberschleissheim | 573.03 mi (922.21 km) |
| Potters Bar to Oberstdorf | 553.91 mi (891.44 km) |
| Potters Bar to Obertraubling | 575.62 mi (926.38 km) |
| Potters Bar to Obertshausen | 408.57 mi (657.54 km) |
| Potters Bar to Oberursel | 394.77 mi (635.31 km) |
| Potters Bar to Ochsenfurt | 470.11 mi (756.57 km) |
| Potters Bar to Ochsenhausen | 515.28 mi (829.26 km) |
| Potters Bar to Ochtrup | 315.80 mi (508.23 km) |
| Potters Bar to Odenthal | 318.09 mi (511.92 km) |
| Potters Bar to Oelde | 356.25 mi (573.33 km) |
| Potters Bar to Oelsnitz | 542.90 mi (873.71 km) |
| Potters Bar to Oer-Erkenschwick | 318.43 mi (512.46 km) |
