Jules Mazellier (6 April 1879 – 6 February 1959) was a French composer and conductor.
Mazellier studied at the Conservatoire de Paris. In 1909 he won the Prix de Rome for his composition La Roussalka. He composed chamber music, works for piano, songs and various operas.
OperaLa Roussalka, Légende russe in 1 act (1909); libretto by Eugène Adénis and Fernand BeissierGraziella, Poème romantique in 4 acts, 5 scenes (1910–1912); libretto by Henri Caïn and Raoul Gastambide; premiere 6 March 1913 in RouenLa villa Médicis, Comédie lyrique in 3 acts (1923); libretto by the composerLes Matines d'Amour (The Bells of Love), Fabliau-miracle en trois images (1927); libretto by Raoul Gastambide; premiere 16 December 1927 at the Théâtre National de L'OpéraOrchestralContemplation, Rêverie (1908)Circenses, Poème symphonique (1911)Impressions d'été, Suite (1911)ConcertanteScherzo, choral et variations sur un thème unique for piano and orchestraChamber musicDivertissement Pastoral for flute and piano (1931)Prélude et Danse for bassoon and piano (1931)Poème Romantique for violin and piano (or orchestra) (1933)Rhapsodie Montagnarde for horn and piano (1933)Nocturne et Rondeau for viola and piano (1934)Fantaisie-Ballet for clarinet and piano (1936)Ballade for violin and pianoBerceuse for violin and pianoChanson for cello and pianoContemplation for violin and pianoFileuse for cello and pianoLégende dramatique for trumpet and piano2 Pièces brèves for flute and piano5 Pièces brèves for cello and pianoPianoBercelonette (1946)Complainte pour Noël, Variations pastorales (1946)Nocturne (1946)VocalLe Livre Chantant, 10 Mélodies for voice and orchestraPrière de Saint-François d'Assise for voice, violin, cello and organPedigogical500 Dictées musicales à une, deux, trois et quatre voix in four volumes 