- Oneida Castle
- Oneonta
- Orange Lake
- Orchard Park
- Oriskany
- Oriskany Falls
- Ossining
- Oswego
- Otego
- Otisville
- Ovid
- Owego
- Oyster Bay
- Oyster Bay Cove
- Oakland Valley
- Odell
- Owego Heights
- Oakes
- Ohioville
- Oliverea
- Oahu Island
- Odell Islands
- Oneida Corners
- Oregon
- Oak Hill
- Ontario Center
- Ontario on the Lake
- Orchard Grove Village Park
- Owls Nest
- Oceola Lake