Karnaval is set against a backdrop of intolerance and hostility in the gloomy Northern French city of Dunkirk. The story is set during carnival time, when the citizens let themselves loose for six weeks of partying, carousing and having a good time. The film centers on Larbi, an Arab youth, and his confrontation with one of the turning points of his life. After a violent argument with his father, Larbi decides to leave the family's business and go to Marseilles for a fresh start. On his last night in the town he grew up in, he sleeps in the hallway of an apartment building, where he is disturbed by Béa and Christian, a couple having fun at the carnival. Larbi is attracted to Béa and decides to stay a few more days to try his luck. In the free atmosphere of the carnival, Larbi discovers a world that he did not know existed, a world which is about to clash with his conservative outlook, and the three lives are changed forever.

Le Carnaval de Dunkerque bat son plein. Après une violente dispute avec son père, Larbi décde de quitter le garage familial et d'aller à Marseille. Alors qu'il passe la nuit sous le porche d'un immeuble, Larbi est reveillé par un jeune couple éméché, Béa et Christian. Mais le jeune homme tombe sous le charme de Béa et décide de rester quelques jours de plus afin de séduire Béa.