| Brussels to Oignies | 64.98 mi (104.58 km) |
| Brussels to Oissel | 178.03 mi (286.51 km) |
| Brussels to Olivet | 233.74 mi (376.17 km) |
| Brussels to Ollioules | 537.13 mi (864.42 km) |
| Brussels to Olonne-sur-Mer | 408.08 mi (656.75 km) |
| Brussels to Oloron-Sainte-Marie | 577.71 mi (929.73 km) |
| Brussels to Onet Village | 455.20 mi (732.57 km) |
| Brussels to Onnaing | 45.82 mi (73.73 km) |
| Brussels to Orange | 463.99 mi (746.73 km) |
| Brussels to Orchies | 54.93 mi (88.40 km) |
| Brussels to Orleans | 231.19 mi (372.07 km) |
| Brussels to Orly | 169.54 mi (272.85 km) |
| Brussels to Ormesson-sur-Marne | 163.75 mi (263.53 km) |
| Brussels to Orsay | 177.10 mi (285.02 km) |
| Brussels to Orthez | 562.17 mi (904.73 km) |
