- O'Brien
- O'Donnell
- Oak Cliff Place
- Oak Grove
- Oak Island
- Oak Leaf
- Oak Point
- Oak Ridge
- Oak Ridge
- Oak Ridge North
- Oak Trail Shores
- Oak Valley
- Oakhurst
- Oakwood
- Odem
- Odessa
- Oglesby
- Oilton
- Old Escobares
- Old River-Winfree
- Olivarez
- Olmito
- Olmos Park
- Olney
- Olton
- Omaha
- Onalaska
- Onion Creek
- Opdyke West
- Orange
- Orange Grove
- Orason Acres Colonia
- Orchard
- Ore City
- Overton
- Ovilla
- Owl Ranch
- Oyster Creek
- Ozona
