Spoiler alert: the title character of Wash Westmoreland’s Colette ends up being kind of a big deal. That shouldn’t be a surprise to anyone familiar with the French author on whom the film is based. Colette, née Sidonie-Gabrielle Colette, has been celebrated as France’s greatest female novelist. But first, she was a wife.

Colette (Keira Knightley) married a bon vivant 14 years her senior who introduced her to Paris salons and other milieus in which one was expected to have “personality with a capital ‘P.’” He was a novelist known singularly as “Willy” (Dominic West). Make that a “literary entrepreneur”: Willy outsourced his authorship, never penning a single word himself but keeping a stable of hungry writers who were willing to uphold his reputation for a few francs that he often couldn’t pay them. But when he was broke, he nevertheless thundered that they should produce more, and quickly.

And one night after Colette entertains with tales of her school days, Willy has an idea: She’ll write his next novel. Surprisingly, she’s happy to do it. Colette churns out the story of Claudine, and soon they have a hit, with demand for more.

It’s Colette’s first step toward wiggling out from under Willy’s thumb. Regardless of the capital-P personality that made her fall in love with him, Willy has proved to be a bit of a trial. He refers to himself in the third person and belches, passes gas, and licks his fingers without regard for company. Worse, he cheats: After one of the times Colette catches him, he defends himself with, “This is what men do! We’re the weaker sex.” She lets loose a deserved “Go to hell!” and storms off.

So Willy thinks he’s sidestepping hypocrisy when he encourages a fling between Colette and another woman. (Though he recoils when he brings up a man. “So cheating for you is a matter of gender,” she correctly sizes up.) Colette isn’t only queer but accepting of gender fluidity; she later has a years-long affair with the Marquise de Belbeuf (Denise Gough), a trans man otherwise known as Missy. Colette and Willy eventually agreed to an open relationship, often socializing with their lovers by their sides.

Colette, co-scripted by Westmoreland (Still Alice), the late Richard Glatzer, and Rebecca D. Lenkiewicz, is therefore a staunchly feminist film, portraying a protagonist who’s bold, broad-minded, and itching for independence. She demands (but doesn’t get) official recognition for the work that her readers seem to know she does anyway, along with the money that’s due to her. But Willy holds the copyright to the Claudine stories and hangs on, surely out of fear of losing his wife. So she begins a second career as a dancer and actress in Paris’ music halls, an occupation that Willy believes is beneath her station and one that causes a scandal when Missy joins her onstage for a kiss.

West is an entertaining if fittingly boorish whirlwind, and his chemistry with Knightley ignites the screen. And she gives one of her fiercest performances as the author who refuses to go down in history as a quiet wife. Divorce and subsequent marriages are in Colette’s future, and Knighley’s turn is sympathetic and cheer-worthy instead of being irritatingly brash. Her Colette won’t be made a fool when it comes to either love or money. As she tells an eyebrow-raising friend, “I’m in on the joke.”

Colette opens Friday at Landmark E Street Cinema, Landmark Bethesda Row Cinema, and Angelika Film Center Mosaic.