Cities in State of California, United States ( 828 )
- North Richmond, California
- North Tustin
- Northridge, California
- Norwalk, California
- Novato
- Nuevo, California
- Oak Hills, California
- Oak Park, California
- Oak View, California
- Oakdale, California
- Oakhurst, California
- Oakland
- Oakley, California
- Oasis
- Oceano, California
- Oceanside, California
- Oildale
- Ojai
- Olivehurst
- Ontario, California
- Opal Cliffs
- Orange, California
- Orange Cove
- Orangevale
- Orcutt
- Orinda
- Orland, California
- Orosi, California
- Oroville, California
- Oroville East
- Oxnard
- Oxnard Shores
- Pacheco, California
- Pacific Grove, California
- Pacifica, California
- Pajaro