Kari Rueslåtten (born 3 October 1973) is a Norwegian soprano singer, songwriter and keyboardist, who was well known for being the former lead singer and songwriter for the now disbanded Norwegian doom metal/experimental band, The 3rd and the Mortal from 1992 to 1994. The 3rd and the Mortal was one of the early bands that used a lead female singer in the metal scene, in which inspired bands such as The Gathering, Flowing Tears and Nightwish.