The Grand Duke; or, The Statutory Duel, is the final Savoy Opera written by librettist W. S. Gilbert and composer Arthur Sullivan, their fourteenth and last opera together. It premiered at the Savoy Theatre on 7 March 1896, and ran for 123 performances. Despite a successful opening night, the production had a relatively short run and was the partnership's only financial failure, and the two men never worked together again. In recent decades, the opera has been revived professionally, first in the US and then in the UK.

Sir William Schwenck Gilbert was an English dramatist, librettist, poet and illustrator best known for his collaboration with composer Arthur Sullivan, which produced fourteen comic operas. The most famous of these include H.M.S. Pinafore, The Pirates of Penzance and one of the most frequently performed works in the history of musical theatre, The Mikado. The popularity of these works was supported for over a century by year-round performances of them, in Britain and abroad, by the repertory company that Gilbert, Sullivan and their producer Richard D'Oyly Carte founded, the D'Oyly Carte Opera Company. These Savoy operas are still frequently performed in the English-speaking world and beyond.