Bacchus is an opera in four acts by Jules Massenet to a French libretto by Catulle Mendès after Greek mythology. It was first performed at the Palais Garnier in Paris on 5 May 1909.

Jules Émile Frédéric Massenet was a French composer of the Romantic era best known for his operas, of which he wrote more than thirty. The two most frequently staged are Manon (1884) and Werther (1892). He also composed oratorios, ballets, orchestral works, incidental music, piano pieces, songs and other music.