Barrios de Texas O
- O'Shea Keleher (4)
- Oak Forest-Garden Oaks (120)
- Oak Grove (2)
- Oak Hills (8)
- Oak Lake (9)
- Oak Lawn (166)
- Oak Park/Northwood (15)
- Oakhurst (1)
- Oakhurst (3)
- Oakwell Farms (5)
- Offatts Bayou (8)
- Old East Dallas (117)
- Old Silk Stocking Historic District (10)
- Old West Austin (15)
- Olmos Park Terrace (2)
- Onion Creek (45)
- Original Town (8)
- OST-South Union (156)
- Outer Comal (285)
- Outer Corpus Christi (1)
- Outer East Fort Worth (73)
- Outer Mission Alton (65)
- Outer N Richland Hill/Haltom City (39)
- Outer Northwest (77)
- Outer West Dallas (32)