Billy Wilder's adaptation of Alexandre Breffort's stage farce stars Shirley MacLaine as the Parisian prostitute of the title. When Nestor Patou (Jack Lemmon) a nave, uncharacteristically honest young gendarme decides to raid Chez Moustache, the bistro which provides a base of operations for many of the Les Halles streetwalkers, including the popular Irma, his boss Inspector Lefevre (Herschel Bernardi) is among the johns, and Nestor quickly finds himself unemployed. But, smitten with Irma, the former cop returns to Les Halles and after a fight with her extortionate pimp Hippolyte (Bruce Yarnell), Nestor takes over his role. As he and Irma become more involved, he becomes increasingly jealous toward her steady parade of customers, and finally resolves to become one. Posing as impotent British aristocrat Lord X, he offers to pay Irma a sizeable sum simply to spend some time with him on a weekly basis. The plot thickens when, on a trip to England, Irma seduces Lord X, whose sexual malady is proven to have been somewhat overstated. Composer Andre Previn won an Oscar for best score.