Louis, who was convicted in 2004 of killing seven mentally impaired young women, died on Sunday morning in a secure hospital in Nancy in eastern France, his lawyer Alain Fraitag told AFP.
As well as the seven murders, Louis was also convicted of raping and torturing his second wife and the sexual assault of her daughter.
Five of the women Louis killed used a bus he drove for social services in the Yonne district of northern Burgundy, from where the seven young women disappeared between 1975 and 1979.