Titus Charles Constantin (born Marseilles 7 January 1835 – died Pau 27 October 1891) was a French conductor, violinist and composer.
He studied at the Paris Conservatoire and in June 1858 entered the composition class of Ambroise Thomas. His compositions include cantatas, a ballet and several orchestral works.
Constantin was music director of the Théâtre des Fantaisies-Parisiennes from 1865 where he revived rare operas by Schubert, Donizetti, Weber, Hérold, Monsigny and Philidor. He also completed and conducted the stage premiere of Mozart’s L'oca del Cairo (as L’oie de Caire) on 6 June 1867 at the Théâtre des Fantaisies-Parisiennes; his version later being heard elsewhere.
Later in the 1860s until 1870 he was conductor at the Théâtre Lyrique. Constantin was then engaged by Daudé as musical director at the Casino in the Rue Cadet from September 1871. He conducted the orchestra in the premiere run of L'Arlésienne by Alphonse Daudet with incidental music by Bizet. Constantin also directed the orchestra at the Théâtre de la Renaissance from March 1873, and was music director at the Paris Opéra-Comique from the death of Deloffre until September 1876.
In the 1870s he conducted at the Théâtre du Capitole de Toulouse and at the Teatro Nacional de São Carlos in Lisbon. His later career was centred around Royan and Pau, where he died.