Young Man's Fancy is a 1939 British historical comedy film directed by Robert Stevenson and starring Anna Lee, Griffith Jones, and Seymour Hicks. The screenplay concerns an aristocratic Englishman who is unhappily engaged to a brewery heiress but meets Ada, an Irish human cannonball, during a visit to a music hall and falls in love with her. Together they are trapped in Paris during the Siege of Paris (1870-1871).

The screenplay was written by Roland Pertwee and Stevenson, with additional dialogue by Rodney Ackland and E.V.H. Emmett. The character of Ada, written especially for Anna Lee by Stevenson, her husband, is "based on Zazel, the original 'human cannon ball', who thrilled London audiences in the [eighteen] nineties by being shot from a cannon" — however, "for the purposes of the film … the period [of the screenplay] has been put back to the seventies".