| Grimbergen to Oignies | 68.75 mi (110.64 km) |
| Grimbergen to Oissel | 182.57 mi (293.82 km) |
| Grimbergen to Olivet | 239.63 mi (385.65 km) |
| Grimbergen to Ollioules | 542.87 mi (873.66 km) |
| Grimbergen to Olonne-sur-Mer | 413.25 mi (665.06 km) |
| Grimbergen to Oloron-Sainte-Marie | 583.69 mi (939.35 km) |
| Grimbergen to Onet Village | 461.33 mi (742.44 km) |
| Grimbergen to Onnaing | 51.02 mi (82.11 km) |
| Grimbergen to Orange | 469.91 mi (756.24 km) |
| Grimbergen to Orchies | 59.06 mi (95.05 km) |
| Grimbergen to Orleans | 237.07 mi (381.54 km) |
| Grimbergen to Orly | 175.34 mi (282.19 km) |
| Grimbergen to Ormesson-sur-Marne | 169.60 mi (272.95 km) |
| Grimbergen to Orsay | 182.83 mi (294.24 km) |
| Grimbergen to Orthez | 568.11 mi (914.28 km) |
