Henri Meilhac (French pronunciation: [ɑ̃ʁi mɛjak]; 23 February 1830 – 6 July 1897) was a prolific French playwright and opera librettist, known for his collaborations with Ludovic Halévy on comic operas with music by Jacques Offenbach. He also wrote occasionally for serious works including Georges Bizet's Carmen (with Halévy) and Jules Massenet's Manon.

Born in Paris, Meilhac began writing for a humorous magazine in 1852, and four years later he began a career as a playwright. In 1860 he collaborated for the first time with Halévy, an old schoolfriend, on a one-act comedy, presented at the Théâtre des Variétés. Over the next twenty-one years the two co-wrote fifty more stage works.

After Halévy retired in 1882 Meilhac continued to write, sometimes as sole author and sometimes with collaborators. His tally of stage works is more than a hundred, and includes short and full-length comic plays and the libretti of twenty-five operettas. He and Halévy wrote the libretti for Offenbach's La belle Hélène (1864), La vie parisienne (1866), La Grande-Duchesse de Gérolstein (1867) and La Périchole (1868). In addition Meilhac provided libretti for operettas by Charles Lecocq, Hervé, Gaston Serpette and Robert Planquette.