Théophile-Jules-Henri "Theo" Marzials (20 December 1850 – 2 February 1920) was a British composer, singer and poet. Marzials was described in 1894 as a "poet and eccentric" by parodist Max Beerbohm, and, after writing and performing several popular songs, vanished into obscurity. His poetry is seen as an example of 19th-century aestheticism.