Catulle Mendès (22 May 1841 - 8 February 1909) was a French poet and man of letters.

Of Jewish extraction, he was born at Bordeaux. He early established himself in Paris, attaining speedy notoriety by the publication in the Revue fantaisiste (1861) of his Roman d'une nuit, for which he was condemned to a month's imprisonment and a fine of 500 francs. He was allied with the Parnassians from the beginning of the movement, and displayed extraordinary metrical skill in his first volume of poems, Philoméla (1863). In later volumes Poésies, première série (1876), which includes much of his earlier verse, Soirs moroses, Contes épiques, Philoméla, etc; Poésies (7 vols., 1885), a new edition largely augmented; Les Poésies de Catulle Mendès (3 vols., 1892); La Grive des vignes (1895), etc., his critics have noted that the elegant verse is distinguished rather by dexterous imitation of different writers than by any marked originality. The versatility and fecundity of Mendes' talent is shown in a series of his critical and dramatic writings, and of novels and short stories, in the latter of which he continues the French tradition of the licentious conte. For the theatre he wrote:

La Part du roi (1872), a one-act verse comedy; Les Frères d'armes (1873), drama; Justice (1877), in three acts, characterized by a hostile critic as a hymn in praise of suicide; the libretto of a light opera, Le Capitaine Fracasse (1878), founded on Théophile Gautiers novel; La Femme de Tabarin (1887); Médée (1898), in three acts and in verse; La Reine Fiammette (1898), a conte dramatique in six acts and in verse, the scene of which is laid in the Italy of the Renaissance; Le Fils de l'étoile (1904), the hero of which is Bar-Cochebas ; the Syrian pseudo-Messiah, for the music of C. Erlanger ; Scarron (1905); Ariane (1906), for the music of Massenet; and Glatigny (1906). His critical work includes: Richard Wagner (1886); LArt au théâtre (3 vols; 1896-1900), a series of dramatic criticisms reprinted from newspapers; and a report addressed to the minister of public instruction and of the fine arts on Le Mouvement poétique francais de 1867 à 1900 (new ed., 1903), which includes a bibliographical and critical dictionary of the French poets of the 19th century.

Perhaps the most famous of his novels are: Le Roi vierge (1880) in which he introduces Louis II of Bavaria and Richard Wagner; La Maison de la vielle (1894), and Gof (1897). He married in 1866 Mlle Judith Gautier , younger daughter of the poet, from whom he was subsequently separated.

On the 8th of February 1909, early in the morning, his dead body was discovered in the railway tunnel of Saint Germain. He had left Paris by the midnight train on the 7th, and it is supposed that, thinking he had arrived at the station, he had opened the door of his compartment while still in the tunnel.