- Ōkawatai
- Okita
- Okitaomote
- Ōkoya
- Ōkubo
- Ōkubodai
- Okutōrisawa
- Ōkuzo
- Ōmachi
- Ōmagari
- Ōmagari
- Ōmagari
- Ōmaki
- Ōmaki
- Ōmatsuzawa
- Omonogawamachi-tsukuriyama
- Omonogawamachi-usui
- Ōmori
- Ōmori
- Ōmori
- Ōmorimachi-hakamagata
- Ōmorimachi-itaida
- Ōmorimachi-sakabe
- Ōmorishita
- Onaginai
- Onarichō
- Onikami
- Onikōbe
- Ōnishigasawa
- Onnagawa