The Royal Gallery of Illustration was a 19th-century performance venue located at 14 Regent Street in London. It was in use between 1850 and 1873.
The gallery was built in the 1820s by the architect John Nash as part of his own house, to display his considerable collection of paintings. In 1850 the building was named the Gallery of Illustration, and between then and 1855 it housed a diorama created and run by the theatrical scene-painters Thomas Grieve and William Telbin.
From 1856 to 1873 the gallery was in the hands of the singer and actress Priscilla Horton and her husband German Reed. Their entertainments developed from songs and comedy with piano accompaniment to programmes of short plays and operettas. In deference to respectable mid-Victorian doubts about the propriety of theatres, the Reeds called their productions "entertainments", and avoided the use of the words "theatre", "play" and other theatrical terms. Under the Reeds the gallery played an important part in the development of a new generation of authors, composers and performers. Among the writers whose works the Reeds staged were W. S. Gilbert and F. C. Burnand, and their composers included Arthur Sullivan, Frederic Clay and Alfred Cellier. The performers Arthur Cecil, Corney Grain and Fanny Holland made their names at the gallery early in their careers.
The lease of the building expired in 1873, and it ceased to be used as a performance venue. The Reeds moved to another theatre, and the gallery became a banqueting hall.