Lekain was the stage name of Henri Louis Cain (31 March 1728 – 8 February 1778), a French actor.
He was born in Paris, the son of a silversmith. He was educated at the Collège Mazarin, and joined an amateur company of players against which the Comédie-Française obtained an injunction. Voltaire supported him for a time and enabled him to act in his private theatre and also before the duchess of Maine.
He made his debut at the Comédie-Française on 14 September 1750 in the role of Titus in Voltaire's Brutus and performed Seïde in Voltaire's Mahomet on 30 September. Owing to the hostility of the actors it was only after a struggle of seventeen months that, by the command of King Louis XV he was accepted at the Comédie-Française (see Troupe of the Comédie-Française in 1752). He had performed the leading role of Orosmane at court in Voltaire's Zaïre, causing Louis XV to declare: "He made me weep, and I never weep." Lekain was made a member of the company on a trial basis at a salary of 12,000 livres per year on 4 January 1751 and was received definitively on 8 February 1752.
His success was immediate. Among his best parts were Herod the Great in Mariamne, Nero in Britannicus and similar tragic roles, in spite of the fact that he was short, stout, and lacking in good looks.
His name is connected with several important scenic reforms. It was he who had the benches removed on which privileged spectators sat obstructing the stage; Count Lauragais paid the excessive indemnity demanded. Lekain also protested against the method of sing-song declamation which was prevalent, and endeavoured to correct the costuming of the plays, although unable to obtain the historic accuracy at which François Joseph Talma aimed.