Set in 1934 Paris, France, the story begins with Richard di Nardo, a young gay hustler, who leaves the apartment of middle-aged Carroll Todd (Robert Preston), also known as Toddy, after a night together. After getting dressed and pocketing some cash from Toddy's wallet, Richard heads out. Meanwhile, Toddy, a performer at Chez Lui, witnesses the club owner, Labisse, casting a judgmental eye on an impoverished soprano named Victoria Grant (Julie Andrews). Although Labisse dismisses her after a disheartening audition, Victoria unexpectedly demonstrates her talent by shattering a wine glass with a sustained pitch, showcasing her astonishing vocal abilities.
Later that night, while dining at a local restaurant, Victoria finds herself torn between paying the rent or indulging in an Italian meal. Her quirky solution to avoid the bill leads to chaos when she drops a cockroach in her salad, resulting in a mad scramble as patrons flee. Amidst this commotion, she and Toddy connect over dinner and end up at Toddy's place, where she seeks refuge from the pouring rain, realizing her clothes had shrunk.
The situation takes a turn when Richard returns to collect his belongings, and Victoria, now donning Richard's clothes, hides in Toddy's closet. In a moment of boldness, she kicks Richard out, leading Toddy to devise a plan to pass Victoria off as a gay female impersonator to the successful agent Andre Cassell (John Rhys-Davies). Cassell buys into the act, introducing her as Count Victor Grazinski, and soon, Victor's popularity skyrockets, captivating club owner King Marchand (James Garner) and his ditzy companion Norma Cassidy (Lesley Ann Warren), along with the tough bodyguard, Bernstein (Alex Karras).
As events unfold, King becomes enamored with Victor, only to experience shock when her true identity is unveiled at the end of a rousing performance. Despite confirming her gender in a sneak peek, King surprisingly plays along, further complicating affairs with Norma and his relationship with Victoria. A series of disputes and misadventures, including a bar brawl and secret rendezvous, lead to humorous yet tumultuous entanglements.
In a twist, when Victoria resolves to drop her alter ego to fully embrace love with King, various pressures—such as King’s partner wanting a share of the club and the persistent suspicion from Labisse—threaten their newfound happiness. Ultimately, Victoria reveals her true self during a climactic showdown at the club, where Toddy, masquerading as "Victor," manages to outwit the Inspector claiming fraud.
As the film reaches its climax, Victoria joins King onstage, stunning him with her unmasked identity while Toddy concludes his pretense with a humorously disastrous but entertaining performance. The film culminates in a joyful celebration of acceptance, as the audience, along with King, Squash, and Cassell, erupts in applause.
