Oh, Kay! is a Broadway musical with book by Guy Bolton and P. G. Wodehouse, lyrics by Ira Gershwin and music by George Gershwin.

It was originally produced at the Imperial Theatre in 1926, starring Gertrude Lawrence and Victor Moore, and was revived at the Century Theatre in 1928. It was revived Off-Broadway in 1960, and a 1990 revival played at the Richard Rodgers Theatre and the Lunt-Fontanne Theatre.

In 1997 a Discovering Lost Musicals concert version played at the Barbican Centre in London, using the original script.

There have been other British productions including one at Chichester.

The plot revolves around the adventures of a bootlegger in Prohibition Era America. The most popular song from the musical is "Someone to Watch Over Me". Oh, Kay! was made into a silent film, but oddly enough, never into a sound motion picture.