Kai Hahto (born in 1973 in Vaasa, Finland) is a Finnish drum-teacher and the drummer of the Finnish metal band Wintersun, and the former drummer of grindcore band Rotten Sound. Beside these, he has played in many other bands, with styles varying from black metal to jazz. He is an endorser for Meinl cymbals, Pearl drums, Pearl Eliminator pedals, Balbex drumsticks, Roland V-Drums and Finfonic earphones. Formerly Hahto played with a handmade Kumu drumkit.