I
- (Minamibōsō Shi) Iriuda
- (Tateyama-shi) Inahara
- (Katsuura-shi) Idemizu
- (Katsuura-shi) Ichinogō
- (Katsuura-shi) Ichinokawa
- (Isumi-gun) Irejuku
- (Isumi Shi) Iwafune
- (Isumi Shi) Ichiba
- (Isumi Shi) Imotoyatsu
- (Isumi Shi) Inarigoshi
- (Isumi Shi) Imazeki
- (Isumi Shi) Irazu
- (Isumi Shi) Iizuka
- (Chōsei-gun) Iwakiri
- (Chōsei-gun) Iwanuma
- (Chōsei-gun) Iriyamazu
- (Chōsei-gun) Ichiba
- (Mobara Shi) Ishigami
- (Mobara Shi) Iwade
- (Chōsei-gun) Iwai
- (Chōsei-gun) Iizawa
- (Chōsei-gun) Ikariyatsu
- (Chōsei-gun) Ichinoseki
- (Chōsei-gun) Ichigataki
- (Isumi-gun) Ishigami
- (Chōsei-gun) Iwakawa
- (Sambu-gun) Isagoda
- (Sodegaura-shi) Inugakubo
- (Sodegaura-shi) Iwaimae
- (Sodegaura-shi) Iwai