| Hoeilaart to Oestrich-Winkel | 164.41 mi (264.60 km) |
| Hoeilaart to Offenburg | 222.07 mi (357.39 km) |
| Hoeilaart to Oftersheim | 206.50 mi (332.32 km) |
| Hoeilaart to Ohrdruf | 273.60 mi (440.32 km) |
| Hoeilaart to Ohringen | 248.37 mi (399.71 km) |
| Hoeilaart to Olbernhau | 387.71 mi (623.97 km) |
| Hoeilaart to Olching | 354.75 mi (570.92 km) |
| Hoeilaart to Oldenburg | 228.93 mi (368.43 km) |
| Hoeilaart to Oldenburg in Holstein | 363.51 mi (585.01 km) |
| Hoeilaart to Olfen | 142.20 mi (228.84 km) |
| Hoeilaart to Olpe | 147.73 mi (237.74 km) |
| Hoeilaart to Olsberg | 179.00 mi (288.07 km) |
| Hoeilaart to Oranienburg | 399.10 mi (642.29 km) |
| Hoeilaart to Ortenberg | 203.36 mi (327.27 km) |
| Hoeilaart to Oschatz | 377.02 mi (606.75 km) |
