Ō
- (Kimitsu Shi) Ōwashi-shinden
- (Kimitsu Shi) Ōi
- (Kimitsu Shi) Ōido
- (Kimitsu Shi) Ōtsuki
- (Kimitsu Shi) Ōshika
- (Kimitsu Shi) Ōyamano
- (Kimitsu Shi) Ōsaku
- (Kimitsu Shi) Ōharadai
- (Futtsu Shi) Ōtsu
- (Awa-gun) Ōkatabira-shimo
- (Awa-gun) Ōkatabira
- (Awa-gun) Ōkatabira-kami
- (Awa-gun) Ōkuzure
- (Awa-gun) Ōsaku
- (Awa-gun) Ōnawa
- (Minamibōsō Shi) Ōsaki
- (Futtsu Shi) Ōyatsu
- (Futtsu Shi) Ōzeki
- (Futtsu Shi) Ōtsuka
- (Futtsu Shi) Ōtsubo
- (Futtsu Shi) Ōmori
- (Futtsu Shi) Ōgawasaki