| Name | What | Region | Country | Lat | Long | Elev ft. | Pop est |
|---|---|---|---|---|---|---|---|
| Ober-Sankt-Veit | city | Wien | Austria | 48.18 | 16.27 | 830 | 310140 |
| Oberlaa | city | Wien | Austria | 48.13 | 16.40 | 830 | 183205 |
| Obersievering | city | Wien | Austria | 48.25 | 16.32 | 830 | 236871 |
| Ochsenhalt | city | Wien | Austria | 48.19 | 16.51 | 830 | 250382 |
| Ottakring | city | Wien | Austria | 48.22 | 16.30 | 830 | 302868 |