OOIOO is a Japanese experimental rock band. The four-piece ensemble was founded by Yoshimi P-We (also known as Yoshimio), the drummer and occasional trumpeter for Boredoms. The band's origin lies in a photo shoot that Yoshimi was asked to do for a magazine. She invited a few of her friends to join her, and they created a fake band for the shoot, which they later decided to make real. The band quickly gained attention by being the opening act for Sonic Youth in 1997 on their Japan tour.

According to AllMusic's Kieran McCarthy "It's next to impossible to describe their sound, because — by design — it rarely follows consistent patterns". Some of their music has been described as having "a majestic ebb and flow that suggests natural wonders" or a "witchy, tribal side". Either way, at any one time it may incorporate chanting and punchy drums, dancey polyrhythms atonal composition or psychedelia.