Jules Delsart (24 November 1844 – 3 July 1900) was a 19th-century French cellist and teacher. He is best known for his arrangement for cello and piano of César Franck's Violin Sonata in A major. Musicologist Lynda MacGregor described Delsart as "one of the foremost French cellists of the period, with faultless technique, a precise bow and a sweet, though not large, tone." He was the owner of the 1689 'Archinto' Stradivari.
Born in Valenciennes in 1844, Delsart began his studies at the Académie de Musique in his native city before transferring to the Conservatoire de Paris, where he earned a premiere prix in cello performance in 1866. His principal teacher was Auguste Franchomme, whom he succeeded as professor of cello at the Conservatoire upon Franchomme's death in 1884. He remained in that position for the rest of his life. His students included Paul Bazelaire,Horace Britt,Marcel Casadesus,Louis Feuillard(this is probably Louis Feuillade),Louis Fournier,Víctor Mirecki Larramat, Henri Mulet, and Georges Papin.
Following his graduation from the Paris Conservatoire, Delsart embarked on several successful tours throughout Europe. On 26 February 1881 he premiered in the Salle Pleyel the cello sonata of Marie Jaëll, with the composer playing the piano. In 1882 she dedicated her cello concerto to him. He made numerous appearances in London, including performing in the world premiere of David Popper's Requiem for three cellos and orchestra alongside the composer and Edward Howell as his fellow cellists at St James's Hall on 25 November 1891. In 1892, at La Trompette, accompanied by Louis Breitner, he premiered Chant saphique, Op. 91, a piece for cello and piano by Camille Saint-Saëns, which was dedicated to him. Other works dedicated to Delsart included David Popper's Nocturne, Léon Boëllmann's Cello Sonata, and Benjamin Godard's On the Lake.