The morning after Miss Potter premiered in 2006, introducing a 12-year-old Lucy Boynton as the young Beatrix Potter, The Telegraph published a piece by her mother, the writer Adriaane Pielou, with the headline ‘My Lucy, the film star’. To this day, Boynton has never read the story.

It’s a telling anecdote about a performer who, 17 years on from her professional debut, still feels uneasy about the term ‘star’, despite a string of high-profile roles on both the big and the small screens, including as Freddie Mercury’s partner Mary Austin in Bohemian Rhapsody, the undercover agent Jean Courtney in The Ipcress File and the ruthless Astrid Sloan in Netflix’s hit show The Politician. "You wouldn’t think I’m the actress in the family," she says. "As a child, I remember being really shy and uncomfortable, and in the shadow of my older sister [Emma-Louise Boynton, who now hosts the podcast Sex Talks]. But I think acting gave me access to change myself somehow... It unlocked the idea that I could be different."

lucy boynton
Pamela Hanson
White gold and diamond pendant, Van Cleef & Arpels

Whatever her technique, it has clearly worked; Boynton emanates a calm, quiet dignity that is its own kind of star quality. She arrives at the Hoxton hotel in Holborn for our interview wearing a black, collared dress with gold embellishment by the Milan-based label Vivetta, her hair newly transformed from platinum-blonde to auburn. With a wardrobe that combines fairy-tale gowns and edgier, retro-inspired looks, she has become a red-carpet favourite with brands from Chanel to Erdem. "The publicity side of things still feels a step away from who I really am, but I’ve found a way to take the pressure off those moments by thinking of them like costume fittings," says Boynton.

It’s hard to sit still when you’re surrounded by so much inspiration

She has a level-headedness about her that contradicts the usual doomsday narrative of the child star who peaks too soon, perhaps because she has always seen performing as "a job, not an identity". "It helps that I started my career in the UK where, at the time, the highest form of acting was being in a BBC period piece," she adds. "In the States, the whole concept of Hollywood makes success feel unattainable." Not that Hollywood is beyond her reach: the frenzy of media interest that Bohemian Rhapsody generated meant that Boynton’s name is now well-known on both sides of the pond, particularly since she started dating her co-star Rami Malek. (She is intensely private about their life together, which sees them spend time in both London and LA, though she does credit her journalist parents, who travelled frequently, with showing her how to "navigate long-distance relationships seamlessly".) More important to her than the widespread recognition that came with such a role, however, is the possibility that it might direct viewers to other, lesser-seen projects – "ones that I’m especially proud of, like Sing Street", she says, referring to the 2016 Golden Globe-nominated musical drama, in which she played an aspiring model living in 1980s Dublin. That performance was indeed one of her most skilful, conveying the curious blend of outward confidence and inward insecurity that makes adolescence so hard.

lucy boynton
Pamela Hanson
Mesh bodysuit; tulle dress, both Alexander McQueen. White and rose gold and diamond necklace, Van Cleef & Arpels

The opportunity to take on psychologically complex characters explains Boynton’s attraction to horror as a genre; her back catalogue includes parts in the supernatural thriller The Blackcoat’s Daughter, the sinister indie hit Don’t Knock Twice and the recently aired Netflix mystery The Pale Blue Eye, a fictional tale of how a young Edgar Allan Poe becomes embroiled in solving a murder case. "I always gravitate towards dark stuff," she says. "I think it’s a really interesting vehicle to talk about the loss of self." In The Pale Blue Eye, she plays the ailing Lea Marquis, whose "constant battle between the way she’s perceived versus the way she feels" reaches a dramatic climax that Boynton clearly delights in enacting.

preview for The Pale Blue Eye trailer (Netflix)
I’ve realised I have more ideas than I’d given myself credit for

By contrast, the opportunity to portray Marie Antoinette – an iconic role, but one that comes with a lot of preconceptions – in the forthcoming film Chevalier required some soul-searching. "I was hesitant at first... I questioned whether we really needed a voice like hers," says Boynton, who embarked on an in-depth period of research about the much-ridiculed historical figure. "I had to check myself, because I realised the historical presentation of this woman was coloured by her gender, and the villainy ascribed to her is what has been ascribed to women throughout history." She offsets the privilege and frivolity that remain undeniable facets of Marie Antoinette’s story with an element of vulnerability.

lucy boynton
Pamela Hanson
Silk tulle and lace dress, Bora Aksu. Satin heels, Gina. White gold and diamond earrings; white gold and diamond ring, both Van Cleef & Arpels

A great reader, Boynton has always known how to translate the words in a book or script into a convincing performance, but she is increasingly gaining confidence when it comes to developing – and voicing – her own ideas ("I’ve realised I have a lot more of them than I’d given myself credit for"). With production underway for a film and two television series in 2023, she will have plenty of opportunities to flex her creative muscles, while also finding time to "flesh out life outside of work". "Going from character to character can be addictive, and it’s hard to sit still when you’re surrounded by so much inspiration, but I’m very conscious of not leaning into that exhaustion if I want to preserve my sanity," she says. And with that, the film star in front of me packs up her things and makes her way out of the hotel, off to meet friends to whom she is still just plain Lucy.

sheila atim lucy boynton shalom brune franklin
Pamela Hanson
Lucy Boynton wears embroidered mesh and tulle dress; boots, both Alexander McQueen. Gold and diamond necklace, Van Cleef & Arpels. Shalom Brune-Franklin wears body, dress, ballerina pumps, all Simone Rocha. White gold and diamond earrings, Van Cleef & Arpels. Atim wears tulle dress, Erdem. Lambskin shoes, Roisin Pierce. White gold and diamond earrings; rose gold and diamond bracelet, both Van Cleef & Arpels

The February issue of Harper's Bazaar UK, starring Lucy Boynton, Shalom Brune-Franklin and Sheila Atim, is out now.