- Old Ford Acres
- Old Fort Estates
- Old Heritage Farm
- Old Mill Chase
- Old Mill Trace
- Old National East
- Old Rock Hill
- Old Sardis
- Old South
- Old Suwanee Estates
- Old Tallapoosa
- Old Town
- Old Villa Rica
- Olde Federal Pointe
- Oldnor Island
- Olifftown
- Olive Branch
- Olive Terrace
- Oliver
- Olivers Mill
- Ollie
- Olney
- Omaha
- Omaha Springs
- Omega
- Onslow Island
- Oostanaula
- Ophir
- Oran
- Orange