Théodore Rousseau (tāōdôr´ rōōsō´), 1812–67, French landscape painter; leader of the Barbizon school. He first received recognition in the Salon of 1848 and was commissioned by the state to paint his Sortie de la forêt de Fontainebleau (Louvre). Thereafter he enjoyed a modest success and lived simply in Barbizon near his friend J. F. Millet. Rousseau's landscapes are grave and full of a deep love of solitude. He is best represented in the Metropolitan Museum and in the Louvre.