When she was just twenty, Jane Birkin made her film debut with a jaw-dropping, risqué appearance in Michelangelo Antonioni’s neo-noir thriller Blow-Up. The wide-eyed British actress quickly earned fans for her boldness and nonchalance on camera, as well as for her effortlessly chic style off it.

Historically, Birkin is tied to the legendary rakish singer-songwriter Serge Gainsbourg. They met on the set of 1969 film Slogan (Birkin starred; Gainsbourg scored the film), but their artistic partnership was ignited when she replaced his ex-girlfriend and collaborator Brigitte Bardot on Gainsbourg’s scandalous song “Je t’aime… moi non plus.” The track featured Gainsbourg and Birkin moaning suggestively, and was condemned by the Catholic Church and the BBC. Due to this publicity, the song became a massive hit and cemented Birkin’s devil-may-care reputation.

Their romance ended twelve years later, when Birkin left Gainsbourg for French film director Jacques Doillon, but their creative partnership lasted until Gainsbourg passed away, in 1991. Birkin has kept the collaboration alive with a short film, Mes images privées de Serge, that looks back on their life together, and with a musical revue of his work, Birkin Gainsbourg: Le symphonique, which she performed at New York’s Carnegie Hall.

When she wasn’t making music with Gainsbourg, Birkin was starring in complex, nuanced films by Doillon, Jacques Rivette, and Agnès Varda; in 1985 she made her onstage debut. She is the mother of actress and musician Charlotte Gainsbourg, singer-songwriter Lou Doillon, and the late photographer Kate Barry. Birkin has received both the British O.B.E. and the French National Order of Merit for her work with Amnesty International and other humanitarian organizations.

I interviewed the icon when she was visiting New York City. Dressed casually in jeans and a cashmere sweater, Birkin kept her namesake Hermès Birkin bag at her feet during our conversation. We sat in the empty nightclub at the top of the Standard High Line hotel, overlooking the city—a terrifying sight for Birkin, who was suffering from vertigo. She resolved the issue by turning her chair sideways to avoid the view.

—Melissa Locker

I. “A TRICKY TIME FOR A TREE HOUSE”

THE BELIEVER: Do you find anything scandalous these days?

JANE BIRKIN: No, not like other people find everything scandalous.

BLVR: Do you feel like one of the benefits of getting older is that you can do absolutely anything you want, frivolous or not?

JB: Anything. The even nicer thing is that you can say to a girl, without it being dodgy in any way, “Oh, you’re really beautiful.” Or I had a spectacularly beautiful taxi driver the other day. At least I thought he was, and I was able to...