Washington appoints a small-minded social butterfly as a U.S. Ambassador in this film adaptation based on the satirical stage musical. When Sally Adams (Ethel Merman) arrives in Lichtenburg, her bright personality charms everyone she meets. She slips her political obligations aside to focus on a budding romance with Cosmo Constantine (George Sanders), the country's foreign minister -- and at the same time, her attaché (Donald O'Connor) pursues a relationship with the princess.