| Willebroek to Oestrich-Winkel | 175.74 mi (282.82 km) |
| Willebroek to Offenburg | 239.96 mi (386.17 km) |
| Willebroek to Oftersheim | 220.19 mi (354.36 km) |
| Willebroek to Ohrdruf | 277.53 mi (446.64 km) |
| Willebroek to Ohringen | 261.30 mi (420.52 km) |
| Willebroek to Olbernhau | 391.73 mi (630.44 km) |
| Willebroek to Olching | 368.49 mi (593.03 km) |
| Willebroek to Oldenburg | 217.33 mi (349.75 km) |
| Willebroek to Oldenburg in Holstein | 352.47 mi (567.25 km) |
| Willebroek to Olfen | 137.58 mi (221.41 km) |
| Willebroek to Olpe | 150.62 mi (242.41 km) |
| Willebroek to Olsberg | 179.24 mi (288.46 km) |
| Willebroek to Oranienburg | 395.35 mi (636.25 km) |
| Willebroek to Ortenberg | 210.89 mi (339.40 km) |
| Willebroek to Oschatz | 378.67 mi (609.41 km) |
