Barrios de Texas O
- O'Shea Keleher (5)
- Oak Forest-Garden Oaks (134)
- Oak Grove (4)
- Oak Hills (9)
- Oak Lake (8)
- Oak Lawn (154)
- Oak Park/Northwood (16)
- Oakhurst (4)
- Oakhurst (4)
- Oakwell Farms (5)
- Offatts Bayou (11)
- Old East Dallas (130)
- Old Silk Stocking Historic District (8)
- Old Town Spring (1)
- Old West Austin (15)
- Olmos Park Terrace (6)
- Onion Creek (39)
- Original Town (8)
- OST-South Union (159)
- Outer Comal (272)
- Outer Corpus Christi (3)
- Outer East Fort Worth (68)
- Outer Fort Bliss/Biggs Field (1)
- Outer Mission Alton (53)
- Outer N Richland Hill/Haltom City (36)
- Outer Northwest (70)
- Outer Socorro (2)
- Outer West Dallas (24)