Lemaître was born in Vennecy, Loiret. He became a professor at the University of Grenoble in 1883, but was already well known for his literary criticism, and in 1884 he resigned his position to devote his time to literature. Lemaître succeeded Jean-Jacques Weiss as drama critic of the Journal des Débats, and subsequently filled the same office on the Revue des Deux Mondes. His literary studies were collected under the title of Les Contemporains (7 series, 1886–99), and his dramatic feuilletons as Impressions de Théàtre (10 series, 1888–98).
