Missouri Neighborhoods O
- O'Fallon Park (2)
- O'Fallon St Charles (47)
- Oak Park Northwest (3)
- Oak Park Southeast (3)
- Oak Park Southwest (6)
- Oakville (7)
- Oakwood (1)
- Old Shoe Factory District (2)
- Old Town South (1)
- Old Westport (6)
- Oldham Farms (4)
- Ott-Chrisman (4)
- Outer North Springfield (26)
- Outer Southeast Springfield (42)
- Outer Southwest Springfield (84)