I
- (Tōkamachi-shi) Ichinosawa
- (Murakami Shi) Iwasawa
- (Murakami Shi) Imoji
- (Sado Shi) Iwakubi
- (Kashiwazaki Shi) Iizuka
- (Santō-gun) Ichinotsubo
- (Nagaoka Shi) Iijima
- (Nagaoka Shi) Iwano
- (Nagaoka Shi) Ichinokai
- (Ojiya-shi) Ikenotaira
- (Ojiya-shi) Ichinokuchi
- (Minamiuonuma Shi) Ichinoe-hei
- (Niigata Shi) Izui
- (Minamiuonuma Shi) Ikazuchi
- (Sanjō Shi) Iida
- (Niigata Shi) Ishize
- (Niigata Shi) Ibarajima
- (Niigata Shi) Inugaeri-shinden
- (Kamo Shi) Iwano
- (Higashikambara-gun) Ishito
- (Higashikambara-gun) Ikazawa
- (Agano Shi) Imaita
- (Shibata Shi) Ishiki
- (Sado Shi) Ishina
- (Santō-gun) Izumozaki
- (Sado Shi) Iwayaguchi
- (Niigata Shi) Iwamuro-onsen
- (Murakami Shi) Iwagasaki
- (Murakami Shi) Iwafune
- (Nagaoka Shi) Iwada