| Welwyn Garden City to Oberkirch | 430.08 mi (692.14 km) |
| Welwyn Garden City to Obernburg am Main | 429.12 mi (690.60 km) |
| Welwyn Garden City to Obernkirchen | 396.75 mi (638.51 km) |
| Welwyn Garden City to Oberschleissheim | 576.03 mi (927.03 km) |
| Welwyn Garden City to Oberstdorf | 557.87 mi (897.80 km) |
| Welwyn Garden City to Obertraubling | 577.93 mi (930.10 km) |
| Welwyn Garden City to Obertshausen | 410.68 mi (660.92 km) |
| Welwyn Garden City to Oberursel | 396.78 mi (638.55 km) |
| Welwyn Garden City to Ochsenfurt | 472.33 mi (760.15 km) |
| Welwyn Garden City to Ochsenhausen | 518.89 mi (835.07 km) |
| Welwyn Garden City to Ochtrup | 315.11 mi (507.12 km) |
| Welwyn Garden City to Odenthal | 319.32 mi (513.89 km) |
| Welwyn Garden City to Oelde | 356.14 mi (573.15 km) |
| Welwyn Garden City to Oelsnitz | 543.97 mi (875.44 km) |
| Welwyn Garden City to Oer-Erkenschwick | 318.66 mi (512.84 km) |
