Ō
- (Kamiamakusa Shi) Ōsaginoura
- (Kamiamakusa Shi) Ōyanomachi-iwa
- (Kamiamakusa Shi) Ōzakura
- (Kamiamakusa Shi) Ōbira
- (Kamiamakusa Shi) Ōyama
- (Kamiamakusa Shi) Ōsakuyama
- (Amakusa Gun) Ōdake
- (Arao Shi) Ōshimamachi
- (Arao Shi) Ōshima
- (Tamana Shi) Ōbiraki
- (Tamana Shi) Ōkura
- (Tamana Shi) Ōkura-danchi
- (Tamana Shi) Ōsō
O
- (Kamiamakusa Shi) Onitsuka
- (Tamana-gun) Orisaki
- (Tamana-gun) Oriji
- (Arao Shi) Ono
- (Tamana Shi) Okieboshi
- (Tamana Shi) Ota
- (Tamana Shi) Onojiri
- (Tamana Shi) Oshima
- (Tamana Shi) Okuno
- (Tamana Shi) Oka
- (Tamana Shi) Ozaki
- (Tamana-gun) Osakamoto
- (Tamana-gun) Ochibaru
- (Yamaga Shi) Odake
- (Yamaga Shi) Obaru
- (Yamaga Shi) Odoshi
- (Yamaga Shi) Onoue