City | 2024 Population |
|---|---|
| O'Brien | 88 |
| O'Donnell | 730 |
| Oak Grove | 807 |
| Oak Island | 178 |
| Oak Leaf | 1,744 |
| Oak Point | 7,424 |
| Oak Ridge | 277 |
| Oak Ridge North | 2,940 |
| Oak Trail Shores | 3,750 |
| Oak Valley | 428 |
| Oakhurst | 21 |
| Oakwood | 407 |
| Odem | 2,242 |
| Odessa | 110,886 |
| Oglesby | 441 |
| Oilton | 90 |
| Oklaunion | 44 |
| Old River-Winfree | 1,317 |
| Olivarez | 6,413 |
| Olivia Lopez Gutierrez | 180 |
| Olmito | 580 |
| Olmito Olmito | 305 |
| Olmos Park | 2,151 |
| Olney | 3,003 |
| Olton | 1,890 |
| Omaha | 939 |
| Onalaska | 3,342 |
| Opdyke West | 224 |
| Orange | 18,873 |
| Orange Grove | 1,200 |
| Orason | 639 |
| Orchard | 320 |
| Ore City | 1,196 |
| Overton | 2,315 |
| Ovilla | 4,474 |
| Oyster Creek | 1,220 |
| Ozona | 2,232 |