The International Gilbert and Sullivan Festival was founded in 1994 by Ian Smith and his son Neil and is held every summer in England. The two- or three-week Festival of Gilbert and Sullivan opera performances and fringe events attracts thousands of visitors, including performers, supporters, and G&S enthusiasts from around the world. The Festival was held in Buxton, Derbyshire, from 1994 to 2013, and from 2014 to 2022, it was held in Harrogate, North Yorkshire, usually with a week in Buxton preceding the main part of the Festival. The entire Festival returned to Buxton in 2023, where it continues.
At the Festival, there are both professional and amateur Gilbert and Sullivan performances. Among the professional offerings are performances each year by the Festival's homegrown National Gilbert & Sullivan Opera Company. Amateur Gilbert and Sullivan performing societies from around the world perform on the Festival's main stage each year. A smaller nearby theatre and other venues host the Festival fringe, which consists of dozens of performances, including a Unifest competition among university groups, and lectures, a memorabilia fair, and other events.