Honestly, if you've been watching anything on British TV or streaming platforms lately, you’ve probably asked yourself: what has Sian Clifford been in? It’s a fair question. She’s one of those actors who seems to have suddenly become the glue holding half the prestige dramas of the 2020s together.
Most people know her as Claire. You know the one—the "hair is everything" sister from Fleabag. But if you think that’s her only trick, you’re missing out on some of the weirdest, funniest, and most heartbreaking performances on screen right now.
From 2024 through 2026, her career has basically hit hyperdrive.
The Breakthrough: Why Claire Changed Everything
Before we get into the new stuff, we have to talk about Fleabag. Sian Clifford and Phoebe Waller-Bridge weren't just co-stars; they were real-life friends who’d been grinding in the London theater scene for a decade. When Sian landed the role of Claire, she didn't just play a sister. She played the embodiment of every person who has ever had a nervous breakdown while wearing a power suit.
She won a BAFTA for it. She got an Emmy nomination. Basically, the industry collectively realized that she could do "repressed rage" better than anyone else alive.
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What Has Sian Clifford Been In Recently?
If you're looking for her more recent work, things have shifted from indie comedies to massive global franchises. In 2024, she made a splash in the Doctor Who finale, "Empire of Death," playing the Kind Woman. It was a role that had fans theorizing for weeks.
Then there’s the Disney+ original film Young Woman and the Sea (2024), where she played Charlotte. It showed a totally different side of her—less "high-strung Londoner" and more grounded period-piece drama.
The Netflix Era and Voice Work
She’s also become a staple on Netflix. If you haven't seen Unstable, you're sleeping on a great workplace comedy. She plays Anna Bennet, the CFO who has to manage Rob Lowe’s chaotic tech genius character. It’s a perfect showcase for her deadpan delivery.
Interestingly, she’s been doing a lot of voice work too.
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- Star Wars: The Bad Batch: She voiced GS-8.
- The Magician’s Elephant: She played Gloria Matienne in this 2023 animated feature.
- Robot Chicken: She’s even done voices for this, including a Maleficent parody.
The 2025 and 2026 Slate: Darker, Weirder Roles
Looking ahead, the answer to what has Sian Clifford been in is about to get a lot more interesting.
The biggest project on the horizon is Mother Mary, directed by David Lowery and released by A24. It’s scheduled for an April 24, 2026 release. It’s a psychosexual pop melodrama starring Anne Hathaway and Michaela Coel. Sian plays a character named Jade. This is a massive jump into the A24 "prestige horror/drama" world, and it's easily one of the most anticipated movies of 2026.
Then there’s Lady. This one is kinda wild.
It’s a mockumentary satire directed by Samuel Abrahams. Sian plays Lady Isabella, a lonely, narcissistic aristocrat who invites a film crew to document her life. Here’s the twist: it’s mixed with magical realism. Her character literally starts becoming invisible. Critics who saw it at film festivals in late 2025 have called it a mix of Saltburn and Fleabag, which sounds like a fever dream in the best way.
A Quick Cheat Sheet of Key Roles
If you're trying to catch up on her filmography, here’s a messy, non-alphabetical list of things you should actually watch:
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- Quiz (2020): She plays Diana Ingram, the wife of the "Coughing Major" from Who Wants to Be a Millionaire. It’s a masterclass in ambiguity. Did they cheat? She makes you wonder.
- Life After Life (2022): A gorgeous, heavy BBC adaptation where she plays Sylvie Todd.
- Chevalier (2022): She’s Madame de Genlis in this lavish period drama about the "Black Mozart."
- See How They Run (2022): A fun whodunnit where she plays Edana Romney.
- Two Weeks to Live: She co-stars with Maisie Williams in this dark comedy. Sian plays a survivalist mother, and it’s surprisingly action-heavy.
Why She’s the Expert of "The Mask"
What makes her good? Honestly, it’s her face. She can look like she’s perfectly in control while her eyes tell you she’s about to scream. That "mask" is what made Claire iconic, and it’s what she brings to roles like the Accountant in Hitmen or Martha Crawley in Vanity Fair.
She spent ten years doing "Off West End" theater before she became a household name. You can see that training in how she handles dialogue—she never wastes a syllable.
Next Steps for Fans
If you want to stay updated on her latest projects, keep an eye on the A24 release schedule for Mother Mary this spring. Most of her recent work like Unstable and Everyone Else Burns (Season 2) is currently streaming on Netflix and Channel 4 respectively. If you’re in the UK, Lady is expected to hit theaters or major streaming platforms following its successful festival run in early 2026.
Check out Quiz if you want to see her best dramatic work outside of the comedy genre; it's arguably her most nuanced performance to date.