On a Monday, early July, Nicolas (David Bursztein), a young and upcoming painter, visits a reclusive but famous painter Edouard Frenhofer (Michel Piccoli) along with his girlfriend Marianne (Emmanuelle Béart). Frenhofer lives quietly with his wife and one of his former models Liz (Jane Birkin) in a rambling château in the French countryside. They are introduced by Porbus Balthazar (Gilles Arbona) an admirer of Nicolas's work and a former lover of Liz. Porbus is a chemist who made his fortune by inventing a chemical formula and now is an art collector.In his prime, Frenhofer was an extremely productive painter. But of late he has not been working with his last art exhibition being over ten years ago. However, he lives a comfortable life with his wife and a housekeeper Françoise (Marie-Claude Roger) and her daughter Magali (Marie Belluc). We also come to know that Marianne is a writer and has published a children's book and that Liz loves practice taxidermy as a hobby with many rare and endangered birds in her collection.During a visit to Frenhofer's studio and later at dinner, Frenhofer recounts starting a masterpiece titled "La Belle Noiseuse" after reading about a 17th century courtesan named Catherine Lescault with his wife as the model for the painting. However, he was not able to finish it and regrets not 'going all the way'. On Balthazar's and Nicolas's suggestion of using Marianne to be his muse for restarting the work on "La Belle Noiseuse", he agrees. Nicolas and Marianne have a fight over Nicolas agreeing to this without asking her first.However, the next day, Marianne goes to Frenhofer's chateau to pose for him in nude. At first they are both slightly awkward with each other with Frenhofer making a few mistakes while sketching her. However, the next day, Frenhofer demands more from her, making her to pose in contorted positions as he wants the real Marianne to come out in the painting and is prepared to even break her to achieve this. He sketches several drawings but is not able to get what he wants. On the third day, Marianne begins to assert herself in the painting process by doing what she feels like to get her emotions out into the canvass. Finally, Frenhofer is able to get what he wants and completes the painting.Meanwhile, Nicolas grows increasing uncomfortable with Marianne posing for Frenhofer as he fears that he might lose her. He confides this to Liz who reassures him that Frenhofer is a gentleman. Also, Marianne refuses to stop posing for Frenhofer and ridicules Nicolas's hypocrisy. Nicolas confides this to his sister Julienne (Marianne Denicourt) who manages his artworks for him. This prompts her to drive all the way to the village to visit him. Also, Liz who discovers, by accident, that Frenhofer has painted the new "La Belle Noiseuse" over the old one for which she had posed, becomes unhappy and considers this a betrayal. She also warns Marianne to not look at the painting after it has been finished as she may not like what she sees.Once the painting is finished, Frenhofer invites Marianne to see it. After seeing the painting, she leaves in a huff, later confiding to Julienne that she found the painting to be cold and dry which she thinks is a true reflection of her personality. Frenhofer later covers up the painting and with the help of Magali hides it behind a brick wall and asks Magali to keep this secret forever. He then proceeds to paint another painting which he displays to everyone the next day as the "La Belle Noiseuse". Marianne and Liz are happy that he did not display the real painting and they reconcile with their respective partners.