| Houghton Regis to Oberkirch | 445.73 mi (717.34 km) |
| Houghton Regis to Obernburg am Main | 444.53 mi (715.39 km) |
| Houghton Regis to Obernkirchen | 409.85 mi (659.60 km) |
| Houghton Regis to Oberschleissheim | 591.65 mi (952.17 km) |
| Houghton Regis to Oberstdorf | 573.52 mi (922.99 km) |
| Houghton Regis to Obertraubling | 593.35 mi (954.90 km) |
| Houghton Regis to Obertshausen | 426.01 mi (685.60 km) |
| Houghton Regis to Oberursel | 412.07 mi (663.16 km) |
| Houghton Regis to Ochsenfurt | 487.71 mi (784.90 km) |
| Houghton Regis to Ochsenhausen | 534.56 mi (860.30 km) |
| Houghton Regis to Ochtrup | 328.29 mi (528.33 km) |
| Houghton Regis to Odenthal | 334.19 mi (537.82 km) |
| Houghton Regis to Oelde | 369.90 mi (595.30 km) |
| Houghton Regis to Oelsnitz | 558.70 mi (899.14 km) |
| Houghton Regis to Oer-Erkenschwick | 332.76 mi (535.53 km) |
