The Zoo is a one-act comic opera, with music by Arthur Sullivan and a libretto by B. C. Stephenson, writing under the pen name of Bolton Rowe. It premiered on 5 June 1875 at the St. James's Theatre in London, concluding its run five weeks later, on 10 July 1875, at the Haymarket Theatre. There were brief revivals in late 1875, and again in 1879, before the opera was shelved.

The St James's Theatre was in King Street, St James's, London. It opened in 1835 and was demolished in 1957. The theatre was conceived by and built for a popular singer, John Braham; it lost money and after three seasons he retired. A succession of managements over the next forty years also failed to make it a commercial success, and the St James's acquired a reputation as an unlucky theatre. It was not until 1879–1888, under the management of the actors John Hare and Madge and W. H. Kendal that the theatre began to prosper.