Eddy Louiss was born Edouard Louise on May 2, 1941 in Paris, France. Born into a musical family, his father was a trumpet player, and he studied several musical instruments, including trumpet and piano.
In his early teenage years Louiss played in his father's band. In the early 60s he was playing piano in various Paris nightclubs and continuing with his studies. He also sang with the French vocal group Double Six, other members of which included Roger Guérin, Ward Swingle and Christiane Legrand, the sister of Michel Legrand.
Adding the organ to his array of instrumental ability, Louiss played with various jazzmen in the 60s, among them Johnny Griffin, Art Taylor , Dizzy Gillespie, and Stan Getz