| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Ocquière | city | Province de Brabant Wallon | Belgium | 50.68 | 4.67 | 393 | 31476 |
| Odeghien | city | Province de Brabant Wallon | Belgium | 50.70 | 4.33 | 262 | 57378 |
| Odrimont | city | Province de Brabant Wallon | Belgium | 50.70 | 4.47 | 278 | 42455 |
| Offus | city | Province de Brabant Wallon | Belgium | 50.65 | 4.92 | 436 | 13082 |
| Ohain | city | Province de Brabant Wallon | Belgium | 50.70 | 4.47 | 278 | 42455 |
| Oisquercq | city | Province de Brabant Wallon | Belgium | 50.67 | 4.22 | 262 | 47931 |
| Oostkerk | city | Province de Brabant Wallon | Belgium | 50.67 | 4.22 | 262 | 47931 |
| Opgeldenaken | city | Province de Brabant Wallon | Belgium | 50.70 | 4.85 | 367 | 9473 |
| Ophain | city | Province de Brabant Wallon | Belgium | 50.68 | 4.18 | 196 | 40345 |
| Ophain | city | Province de Brabant Wallon | Belgium | 50.67 | 4.35 | 403 | 52373 |
| Ophain-Bois-Seigneur-Isaac | city | Province de Brabant Wallon | Belgium | 50.67 | 4.35 | 403 | 52373 |
| Opheylissem | city | Province de Brabant Wallon | Belgium | 50.75 | 4.98 | 246 | 18405 |
| Opprebais | city | Province de Brabant Wallon | Belgium | 50.68 | 4.80 | 416 | 7621 |
| Orbais | city | Province de Brabant Wallon | Belgium | 50.63 | 4.77 | 485 | 6403 |
| Orival | city | Province de Brabant Wallon | Belgium | 50.62 | 4.30 | 449 | 30095 |
| Orp-le-Grand | city | Province de Brabant Wallon | Belgium | 50.70 | 5.00 | 344 | 9990 |
| Orp-le-Petit | city | Province de Brabant Wallon | Belgium | 50.70 | 4.98 | 308 | 11040 |
| Osage | city | Province de Brabant Wallon | Belgium | 50.60 | 4.42 | 426 | 17064 |
| Ottignies | city | Province de Brabant Wallon | Belgium | 50.67 | 4.57 | 328 | 56627 |