Gustave Adolph Kerker, sometimes given as Gustav or Gustavus Kerker, (February 28, 1857 – June 29, 1923) was a Kingdom of Prussia-born composer and conductor who spent most of his life in the United States. He became a musical director for Broadway theatre productions and wrote the music for a series of operettas and musicals produced on Broadway and in the West End. His most famous musical was The Belle of New York (1897).