Barrios de Texas O
- O'Shea Keleher (9)
- Oak Forest-Garden Oaks (151)
- Oak Grove (4)
- Oak Hills (9)
- Oak Lake (14)
- Oak Lawn (158)
- Oak Park/Northwood (19)
- Oakhurst (5)
- Oakhurst (7)
- Oaklawn (2)
- Oakwell Farms (5)
- Offatts Bayou (12)
- Old East Dallas (148)
- Old Silk Stocking Historic District (9)
- Old Town Spring (8)
- Old West Austin (14)
- Olmos Park Terrace (9)
- Onion Creek (49)
- Original Town (27)
- OST-South Union (186)
- Outer Comal (313)
- Outer Corpus Christi (5)
- Outer East Fort Worth (85)
- Outer Fort Bliss/Biggs Field (1)
- Outer Mission Alton (28)
- Outer N Richland Hill/Haltom City (39)
- Outer Northwest (117)
- Outer Southeast Dallas (3)
- Outer West Dallas (25)