| Welwyn Garden City to Oerlinghausen | 377.77 mi (607.96 km) |
| Welwyn Garden City to Oestrich-Winkel | 377.93 mi (608.22 km) |
| Welwyn Garden City to Offenburg | 427.13 mi (687.40 km) |
| Welwyn Garden City to Oftersheim | 419.87 mi (675.72 km) |
| Welwyn Garden City to Ohrdruf | 476.18 mi (766.34 km) |
| Welwyn Garden City to Ohringen | 462.01 mi (743.53 km) |
| Welwyn Garden City to Olbernhau | 589.55 mi (948.79 km) |
| Welwyn Garden City to Olching | 567.79 mi (913.77 km) |
| Welwyn Garden City to Oldenburg | 365.45 mi (588.13 km) |
| Welwyn Garden City to Oldenburg in Holstein | 490.58 mi (789.51 km) |
| Welwyn Garden City to Olfen | 323.92 mi (521.30 km) |
| Welwyn Garden City to Olpe | 349.99 mi (563.26 km) |
| Welwyn Garden City to Olsberg | 373.66 mi (601.34 km) |
| Welwyn Garden City to Oranienburg | 570.63 mi (918.33 km) |
| Welwyn Garden City to Ortenberg | 413.44 mi (665.37 km) |
