Luis Federico Leloir ForMemRS (September 6, 1906 – December 2, 1987) was an Argentine physician and biochemist who received the 1970 Nobel Prize in Chemistry for his discovery of the metabolic pathways in lactose. 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. His research into sugar nucleotides, carbohydrate metabolism, and renal hypertension garnered international attention and led to significant progress in understanding, diagnosing and treating the congenital disease galactosemia. Luis Leloir is buried in La Recoleta Cemetery, Buenos Aires.