| Birkenhead to Oberkirch | 587.14 mi (944.91 km) |
| Birkenhead to Obernburg am Main | 575.40 mi (926.01 km) |
| Birkenhead to Obernkirchen | 511.75 mi (823.58 km) |
| Birkenhead to Oberschleissheim | 726.98 mi (1,169.96 km) |
| Birkenhead to Oberstdorf | 714.88 mi (1,150.49 km) |
| Birkenhead to Obertraubling | 723.31 mi (1,164.05 km) |
| Birkenhead to Obertshausen | 555.77 mi (894.43 km) |
| Birkenhead to Oberursel | 541.28 mi (871.10 km) |
| Birkenhead to Ochsenfurt | 617.77 mi (994.20 km) |
| Birkenhead to Ochsenhausen | 674.09 mi (1,084.84 km) |
| Birkenhead to Ochtrup | 433.70 mi (697.98 km) |
| Birkenhead to Odenthal | 458.33 mi (737.62 km) |
| Birkenhead to Oelde | 480.06 mi (772.58 km) |
| Birkenhead to Oelsnitz | 677.49 mi (1,090.32 km) |
| Birkenhead to Oer-Erkenschwick | 447.76 mi (720.60 km) |
