Cool Joke is a Japanese rock band formed in 2004. The band's current lineup consists of vocalist Hiroya Ishikawa, guitarist Suguru Asabatake and drummer Hiroyuki Saitō. In addition to Ishikawa, Asabatake and Saitō, the band originally featured bassist Keita Hayashi.

However, Hayashi left the band in 2006. They perform under the Sony Music Japan Records label. During their time as an indie band, their activity was centered in the Fukui prefecture area. They are now performing on a national level, and one of their songs, UNDO, has been used in the popular anime Fullmetal Alchemist.

Singles 1. "UNDO" (May 12, 2004) - third opening theme for the anime Fullmetal Alchemist 2. OK,フルスロットル / "OK, Full Throttle" - (January 19, 2005) 3. 愛のチカラ / "Ai no CHIKARA" - (August 18, 2005) (limited production) 4.

世界は君の手の中に、光は詩の中に / "Sekai wa kimi no te no naka ni, hikari wa shi no naka ni" - (September 21, 2005)Albums 1. COOL JOKE (October 26, 2005) 2. Reality (2008/11/12)