Sydney Grundy was an English dramatist. Most of his works were adaptations of European plays, and many became successful enough to tour throughout the English-speaking world. He is, however, perhaps best remembered today as the librettist of several comic operas, notably Haddon Hall.

Haddon Hall is an English light opera with music by Arthur Sullivan and a libretto by Sydney Grundy. The opera, set at the eponymous hall, dramatises the legend of Dorothy Vernon's elopement with John Manners, resetting the tale in the 17th century.