- Obayashi
- Ochibara
- Ōgi
- Ogino
- Ōgochō-kitahata
- Ōgochō-kitaso’o
- Ōgochō-kizu
- Ōgochō-kōda
- Ōgochō-mikage
- Ōgochō-nose
- Ōgochō-ōgo
- Ōharano
- Ōhata
- Ōjichō
- Ōjika
- Okamoto
- Ōkawase
- Okinoura
- Ōkubochō-eigashima
- Ōkubochō-nishiwaki
- Ōkubochō-ōkubo
- Okuikechō
- Ōno
- Ono
- Onohamachō
- Osaki
- Oshibedanichō-kōmi
- Oshibedanichō-nishimori
- Oshibedanichō-oshibe
- Oshibedanichō-wada