The actor passed away on 29 July (11) in Paris. The cause of death was a heart condition, according to his family.
Laydu, who was born in Belgium, was just 23 when director Robert Bresson picked him to star in his movie Diary of a Country Priest.
The critically acclaimed drama scooped a haul of awards, including the Grand Prize at Italy's Venice International Film Festival.
Laydu went on to star in other films including I Was a Parish Priest and Rasputin, and later wrote a kids' puppet show for TV called Good Night, Little Ones.
He is survived by his wife Christine Balli-Laydu as well as a son and daughter.