- Ōbandokoro
- Ōbasama
- Ōbatake
- Obayashi
- Ōbayashi
- Ochiai
- Odai
- Ōdanbara
- Ōdasawa
- Ōdate
- Ōdateyama
- Ōdomari
- Ōdori
- Ōgai
- Ogaku
- Ogatsuchō-mizuhama
- Ogatsuchō-naburi
- Okatsuchō-okatsu
- Ogatsuchō-ōhama
- Ogatsuchō-ōsu
- Ogatsuchō-tachihama
- Ogatsuchō-wakehama
- Orinohama
- Ōharahama
- Ōhashi
- Ōhatsudaira
- Ōhayashi
- Ōhinata
- Ōhinata
- Ōhinata