Acidman (often stylized as ACIDMAN) is a Japanese rock group. The band was formed in 1997 with four members, Shiibashi Takeshi, Urayama Ichigo, Satou Masatoshi, and Ohki Nobuo. They created two demo tapes together in 1998, but former vocalist Shiibashi Takeshi left in 1999. Ohki Nobuo took his place and became the leader of the group. They continued playing live concerts, and were eventually signed to Toshiba-EMI. The band is often categorized as punk music or alternative rock but their musical style is broader and is said to blend various kinds of individual styles.

Ohki Nobuo paints many of the band's album covers.