Although born in France, Leloir received the majority of his education at the University of Buenos Aires and was director of the private research group Fundación Instituto Campomar until his death in 1987.
Leloir lahir di Prancis namun ia menerima sebagian besar pendidikannya di Universitas Buenos Aires dan menjadi direktur di grup penelitian swasta Fundación Instituto Campomar hingga kematiannya pada tahun 1987.