A painter is helped in his career by a divorced heiress while he falls in love with a young Parisian who is already engaged.
Ex GI Jerry Mulligan (Gene Kelly) stayed in Paris after the war to paint. Singer Henri Baurel (Georges Guétary) tells pianist Adam Cook (Oscar Levant) about 19-year-old Lise. Jerry is broke and borrows lunch money. Henri sings “By Strauss.” Jerry displays his paintings in the street. Milo Roberts (Nina Foch) asks to buy two and takes him to her hotel to pay him the 30,000 francs.
On the street Jerry teaches children English words, sings “I Got Rhythm,” and tap dances. Jerry goes to a party at Milo’s and is the only guest. He takes her to dinner, and she offers to promote his career. Reporter Tommy comes in and has them join him. Jerry is entranced by Lise and gets her to dance with him. On the way home Milo reprimands Jerry, and he gets out of her car.
The next morning Milo apologizes to Jerry and arranges to meet him. He helps Lisa sell perfume to a lady, and they make a date at 9. Jerry sings “Tra-La-La” with Adam and tap dances. Jerry and Lise walk to the river and talk. He sings “Love Is Here to Stay,” and they dance. At 11 she runs off. In his show Henri sings “I’ll Build a Stairway to Paradise.” He tells Lise he wants to marry her and tour America.
Adam ribs Jerry about Milo and fantasizes giving a concert. Milo offers Jerry a better studio and an exhibition in three months. Jerry paints various scenes and kisses Lise. She decides not to tell Jerry about Henri. Jerry tells Adam that he is hooked on Lise. Henri arrives and says he is getting married. Henri advises Jerry to declare his love. Henri and Jerry sing “S’Wonderful.”
At the river Jerry tells Lise that he loves her, but she says she is going to marry Henri in gratitude for his having helped her during the war. Lise tells Jerry that she loves him as she goes.
Jerry asks Milo to break her date and takes her to a New Year’s Eve party. At the party Henri tells Jerry that he and Lise are leaving Paris. Jerry tells Milo that he is in love with Lise. On a balcony Lise says goodbye to Jerry, and Henri overhears.
Jerry imagines himself dancing on a Paris street. He sees Lise and dances with her, but he ends up alone with a rose. Jerry sees Lise coming back to him, and they embrace.
This artistic musical with Gershwin songs depicts an American whose machismo is reluctant to accept help from a wealthy woman with romantic designs. A young woman is loyal to the man who took care of her when she was in need; but she is wooed by the undiscouraged American who has successfully picked her up.