Colette, Keira Knightley is a young woman from the rural Saint-Sauveur-en-Puisaye at the end of the 19th century who begins an affair with Willy. Willy, Dominic West, eventually brings Colette to Paris as his bride, with socialites expressing surprise that a libertine like him would marry. He calls himself a literary entrepreneur, relying on several ghostwriters to draft articles, yet his extravagant lifestyle and constant entertaining of high society drain his finances. To keep up appearances, he hires a ghostwriter to work on a novel while Colette manages his correspondence. When Colette discovers Willy with a prostitute, the couple separates, though he eventually persuades her to return, promising honesty.
Colette also recalls her days as a schoolgirl. As Willy grows ever more unable to pay his writers, he asks Colette to turn a set of her school stories into a novel. She drafts Claudine à l'école, but Willy rejects it for lacking a strong plot. Years pass, and some of Willy’s furniture is repossessed; he discovers the draft, suggests revisions, and the manuscript is published under Willy’s byline. Claudine à l'école becomes a bestseller, especially appealing to a female readership. With this first true hit, Willy tells his publisher that a sequel is coming, purchases a country house, and locks Colette in a room there to coerce her into writing. Initially objecting, Colette completes Claudine à Paris, which becomes another bestseller.
As Colette and Willy grow in fame, she attracts the notice of Georgie Raoul-Duval, a Louisiana debutante, and they begin an affair. Jealous, Willy also begins an affair with Georgie. Colette discovers this, and bases her next book, Claudine en ménage, on the episode. Fearing scandal, Georgie’s husband purchases and burns all copies of the book before sale, but does not purchase the copyright, allowing Willy to reprint and sell the work.
The Claudine books continue to find success, including a stage adaptation starring Polaire. Colette then begins an affair with Missy, who presents as male; they dance and develop an act at the Moulin Rouge that provokes a morally outraged response when they kiss onstage. Willy cites the act as a financial disaster and sells all rights to the Claudine books for 5,000 francs without Colette’s knowledge. Angered and feeling betrayed, Colette leaves Willy. Willy asks his employee Paul to burn the Claudine manuscripts; Paul returns them to Colette instead.
Colette emerges as a writer in her own right, beginning with The Vagabond, published under her byline, drawing on her music-hall experiences.
