Chatmonchy is an all-woman rock band from Tokushima Prefecture on Shikoku, Japan. The group is best known as a duo featuring Eriko Hashimoto on guitar and vocals, alongside bassist and backing vocalist Akiko Fukuoka. They've been with Sony Music Japan's Ki/oon Records since 2005.

The band's lineup has shifted over the years. Yumi Nakamura played bass during their early days (2000–2002), with Erina Ishida on drums that same period. Sonekayo took over drums briefly from 2002 to 2003, followed by Kumiko Takahashi, who joined as drummer and backing vocalist in 2004 and stayed until 2011 (she'd been a support member in 2003 before that).

- Yumi Nakamura (Bass, 2000–2002)

- Erina Ishida (Drums, 2000–2002)

- Sonekayo (Drums, 2002–2003)

- Kumiko Takahashi (Drums, Backing Vocals, 2004–2011; support member 2003)