Naughty Marietta is a musical comedy, with libretto by Rida Johnson Young and music by Victor Herbert, which opened on Broadway on November 7, 1910: one of its best-known songs is Ah! Sweet Mystery Of Life.

In the 1935 movie based on the operetta, Jeanette MacDonald stars as a flirty, flighty Princess who trades places with her maid Marietta in order to avoid an arranged marriage. Instead, she sails for New Orleans, but is captured by the pirate Captain Richard Warrington (Nelson Eddy), with whom she falls in love.

The film was written by Frances Goodrich, Albert Hackett, John Lee Mahin and Rida Johnson Young. It was nominated for the Academy Award for Best Picture. Douglas Shearer won the Academy Award for Sound for his work on the picture. In 2003 the United States Library of Congress deemed the film "culturally significant" and selected it for preservation in the National Film Registry.