William Vincent Wallace (* 11 March 1812 in Waterford, Ireland; † 12 October 1865 in Sauveterre-de-Comminges, Département Haute-Garonne, France) was a British composer and musician.
William Wallace was the son of a Scottish military bandmaster and grew up in Ballina, Ireland. When he moved to Dublin in 1823, he had already practised various instruments in his father's band. In Dublin he learned to play the piano, played second violin in the Theatre Royal and was also organist in the Cathedral of the Assumption in Thurles. In 1831 he married, converted to Catholicism for it and changed his first name to Vincent. At the age of 22 he performed his first violin concerto. Together with his wife, child, a sister and a brother, he emigrated to Australia in 1835, where together they founded the first music school on the continent in Sydney. Wallace ran up debts, separated from his family in 1838 and began an unsteady life as a musician, which first took him to South America. In 1841 he stayed in Mexico City. In New York, he was involved in the founding of the New York Philharmonic Society in 1842. He then worked in Germany and in 1844 in the Netherlands. On 15 November 1845, his opera Maritana was premiered at the Drury Lane Theatre in London. He premiered five more operas at this and other London venues, including the Lore-ley opera Lurline. Five operas remained unperformed. Wallace composed over 50 vocal pieces and some seventy chamber works. Many of his arias appeared as independent printed editions.
In 1850 he married the pianist Helene Stoepel in the USA, with whom he had two children. He acquired US citizenship, but from 1858 he stayed again mainly in Europe. For health reasons he moved with his wife to the Pyrenees, where he died. He was buried in Kensal Green Cemetery in London. Helen Wallace died in New York in 1885.
Wallace was one of the first composers to integrate elements of South American folk music into Western art music. He is considered, together with the also forgotten M. W. Balfe, to be the most successful composer of English-language opera in the 19th century.
After his death in France, he was transferred to London and buried in Kensal Green Cemetery.