The film is set in Viennese high society of about 1900. After a masked carnival ball, Gerda Harrandt (Hilde von Stolz), wife of the surgeon Carl Ludwig Harrandt (Peter Petersen), allows the fashionable artist Ferdinand von Heidenick (Adolf Wohlbrück) to paint a portrait of her wearing only a mask and a muff. This muff however belongs to Anita Keller (Olga Tschechowa), in secret the painter's lover but also the fiancée of the court orchestra director Paul Harrandt (Walter Janssen), the brother of Gerda's husband.
Prince Danilo falls in love with dancer Sally O'Hara. His uncle, King Nikita I of Monteblanco forbids the marriage because she is a commoner. Thinking she has been jilted by her prince, Sally marries old, lecherous Baron Sadoja, whose wealth has kept the kingdom afloat. When he dies suddenly, Sally must be wooed all over again by Danilo.
Playboy, Captain Danilo (Maurice Chevalier), is ordered by King Achmet of Marshovia (George Barbier) to court and marry Madame Sonia (Jeanette MacDonald), a rich widow who owns a large portion of the kingdom.
Der Kongress tanzt takes place during the Congress of Vienna, that took place in 1814/1815 after the Napoleonic Wars, a meeting between the powers that was to set the frontiers of the world.
Un jeune homme et une jeune femme qui ne se connaissent pas partagent la même chambre, lui le jour, elle la nuit, sans jamais se croiser. S'étant rencontrés par hasard en ville, ils tombent amoureux mais ils continuent à ignorer qu'ils occupent la même chambre.
Sir John Falstaff est un fieffé filou. Schürzenjäger et Trunkenbold ont envoyé une lettre d'amour identique à deux femmes. L'une d'elles, Mistress Ford, décide, avec M Reich, de donner une leçon. Mistress Ford invite Falstaff à un rendez-vous à sa maison, tandis que l'autre envoie une lettre à M. Ford pour lui apprendre le rendez-vous de Falstaff avec sa femme.
The film begins in Vienna in the year 1890 and we find that Walter Pidgeon, Alexander Gray and Bert Roach, who are three close friends, are going to join the Austrian army. Eventually, Pidgeon become a lieutenant and as a superior officer he is forced to distance himself from his two former friends. Gray and Pidgeon end up falling in love with a poor girl, played by Vivienne Segal, who is the daughter of a cobbler. Although Segal truly loves Gray, she chooses to marry Pidgeon because of his wealth and position, believing that money and the social mobility that goes with it will bring her happiness. Gray is heartbroken and travels to the United States with his friend Roach. Gray gets a job playing violin in an orchestra but struggles to support his wife and child. In the course of time, Segal travels to the United States and meets Gray and their love is rekindled. Gray learns of Segal's unhappy marriage and they plan to make a new life together. Segal, however, discovers that Gray is married and has a child. Feeling sorry for Gray's son, she sacrifices her happiness and returns to Pidgeon, her husband. The film now progresses forty years in time to the year 1930. Segal is now a grandmother and she is planning for her granddaughter, played by Alice Day, to marry a wealthy man since the family's fortunes are now on the wane. Day, however, falls in love with a composer, who happens to be the grandson of Gray. Segal immediately recalls her romance with Gray and of the mistake she once made. She consents to her granddaughters marriage and reminiscences about the man she really loves, who is now dead. One day after the wedding, while at the park, Segal sees Gray and her spirit walks off with him and leaves her body. The film ends as she is finally reunited with her long lost love.