The 27-year-old rose to fame as the naive, fragile Cassie in HBO’s Euphoria, in which her character is — deep breath — pressured into having an abortion, has a messy affair with her best friend’s abusive boyfriend, and eventually collapses into a chaotic, much-memed bathroom meltdown — while dressed like she’s in the musical Oklahoma!. And Cassie’s demons and dark side set a template for what was to come. As Sweeney’s film career began to take off, she played a Manson girl in Once Upon A Time In Hollywood, starred as a real-life whistleblower interrogated by the FBI in stressful drama Reality, and as a producer, worked for ten years to ensure that Immaculate, in which she plays a novice nun impregnated with the spawn of Satan by evil priests, got made. Now, in new film Echo Valley, she embraces the grit again as the troubled drug-addict Claire, who brings all sorts of pain to her mother’s (Julianne Moore) door. Clearly, Sweeney seems to relish roles that require as little vanity as possible.

No — I am filming Euphoria right now, but I had a little bit of time off. I’m shooting a beauty campaign in Barcelona.

I am. I love to be able to jump fully into these characters and go mad, almost, in the scenes, but if I took that home, that definitely would not be a fun dynamic for my friends and family. I don’t ever put any of my own personal thoughts or memories or feelings into a character. I was taught that by my friend Kodi Smit-McPhee’s dad, Andy (an acting coach). He taught it to me as a way of just making sure that I can have a healthy, balanced life, and being able to know who Sydney is as a person, and then also be able to know who my characters are.

I mean, it’s an emotional release, for sure. It’s definitely a very big emotional release.

Oh, I am obsessed with Julianne Moore. When I found out I was going to do a movie with her... I keep being like, “Oh my gosh, I’m ticking off all these big bucket-list items in my career.” I really hope my thirties can live up to my twenties!

You have to be able to go to those places, because they can be scary. I just let whatever happens with the character happen. I never know what’s going to come out. I don’t know how I’m going to perform a scene. I don’t plan it.

I love the stuff that’s so extremely far from who I am. I think that’s why, if you look at it like that, there are two very extreme versions of the characters I play. Like, the glossy or the crazy. But I hope I fall somewhere in the middle. (Laughs)

I actually filmed those two shows at the same time. And then I filmed The Handmaid’s Tale, and then the pilot of Euphoria. It was a crazy year. But it was also an incredible year, because it was everything that I’d always dreamt of and worked for. These characters that I always hoped I’d be able to audition for one day, they were all coming to life. These incredible women were complex and multi-faceted and they were deep. It was a dream, honestly.

I have such a spot in my heart for Cassie, and I hold her really close and dear. She is crazy. She makes so many mistakes. She’s flawed on so many levels, but she does it all from a place of love. It could be a sad version of love, as well. It’s so much fun to play a character that is as crazy as she is. Sam [Levinson] is such a brilliant filmmaker to work with, because I’ll read something, then I’ll call him, and I’m like, “Let’s go crazier.” And he’s like, “I’m all in.” And this season is unhinged.

(Laughs) Yes.

It definitely changed my life, yeah. I think that with the amount of access, with social media, and how much content gets put out there of Cassie... People do have a hard time separating actors from their characters, and especially someone like Cassie, where she is hated and she’s loved, but she’s definitely a complicated character. And so I think that that could confuse people, for sure. But if they’re hating me for decisions that my character is making, then I’m playing the character correctly.

I think because I’ve loved acting since such a young age, and I always dreamed of playing characters that I’ve been so lucky to be able to play, I knew it wasn’t gonna be all easy. And yeah, you learn. I was 20, filming the pilot of Euphoria, and 21 when it came out. So it was a whirlwind at a really young age. You have to roll with the punches and grow and learn and adapt.

I mean, talk about another bucket-list item I did not think was going to be happening. I spent my 21st birthday on that set. He had a no-phone rule, so everyone just ran around that world, and was present with each other. He’s so fascinating to watch and listen to. He tells so many stories. You feel like you’re a part of what you imagine Hollywood would be.

I love research, so I tried to learn as much as I possibly could. I read a lot. I scrapbooked some stuff. With Snake, she actually had a book that you can read about her. There was a lot of material to go off.

I love to find characters and projects that are completely, vastly different from one another. I had just finished Euphoria, and usually, once a project comes out, you get sent a bunch of scripts that are exactly like that character, or the tone of that project. I kept reading all these things. I was like, “No, I don’t want to do that again,” because I knew they were coming back to Cassie. My agent sent me Reality and said, “Read this,” and I read it, and I was absolutely terrified, because I knew it was going to be a huge challenge. Usually when something scares me or it presents itself as a challenge, I know I have to go after it. And so I put myself on tape and auditioned for it, because they didn’t think I was going to be right for it.

I mean, if you watch Cassie, you’re not going to think Cassie is going to play Reality. I like the projects where I have to prove people wrong. I ended up getting it, and we filmed it in 16 days. It was a very gruelling process, but I’m so incredibly proud of that film.

Just how different a character she was. There’s so much dialogue, and it’s not just dialogue, it’s an actual transcript from the interrogation, and that holds a lot of weight. Her mind is racing and thinking a million things so quickly, and she has to be so present and try and navigate in a situation that’s unfolding in front of her. It was a lot to wrap your head around.

It’s always fun to be able to be a part of something that’s bigger than yourself. I hadn’t done a studio film yet, and I had started my production company [Fifty-Fifty Films]. I had some properties that I really wanted to be able to take out to studios, and I needed to be able to get my name to have more value, within a studio household. Doing a project like that really helps you on in the market. I also wanted to be able to do something that my cousins can watch. I have a bunch of little teenage cousins, and they don’t really understand what I do. I thought it would be so cool to be able to do something that they’d actually think was fun and cool.

I mean, I had a really fun time, so that is all that matters to me. I think that if you are enjoying what you do, it doesn’t really matter what the outcome is, on a box-office level. Of course, you want the film to be celebrated and loved and successful, because then everyone succeeds.

This industry is so fascinating. There are so many chats, pieces and moves to make, and I find that really exhilarating. It’s constantly changing. I love acting, but being able to step outside of that and then see how everything comes together, and understand what every crew member needs and what it takes to get a project from imagination to conception... When people see it in the theatres or on screen, it’s been a really long, hard process, but I love it.

There are movies you do for the critics and there are movies that you do for an audience. Take Reality. Reality is for the critics, and Anyone But You is for an audience.

100 per cent. 1,000 per cent. Critics all have their own opinions, and you can’t just try and make critics happy, because you’re not thinking about everybody else. It’s a different process and a different experience.

(Laughs) Ummmmm! You’ll just have to wait and see. It’s not a no, and it’s not a yes. It’s a, “I don’t have an answer that I can say for you.”

I grew up loving romcoms. I am a hopeless romantic, so I love those kinds of films. My Best Friend’s Wedding, 13 Going On 30, Crazy Stupid Love, 50 First Dates, When Harry Met Sally...

I’ve got all sorts of stuff that we just finished. ‘Christy Martin’ (an as-yet untitled biopic of the pioneering female boxer), which I’m really, really proud of, and very excited for people to see. I produced The Housemaid (a Paul Feig-directed adaptation of a bestselling thriller), with Amanda Seyfried and Brandon Sklenar. I am producing Scandalous!, which Colman Domingo will be directing (about the love affair between Sammy Davis Jr. and Kim Novak, who will be played by Sweeney). And a few others that  
I can’t talk about.

I thrive in chaos. I love working. I love having to juggle multiple things at the same time. I don’t really sleep much, but I do best when I don’t sleep much.

I auditioned for it when I was 16, and they never made the movie. And I just never stopped thinking about it, and I really wanted to see if I could bring it to life. I took the script out to financiers, and hired our director Michael Mohan, who I had worked with before on Everything Sucks and The Voyeurs. My biggest fear was hiring a director that would take it from me, and I’d feel like I lost my baby and I didn’t have any creative say. That because it was my first film that I was producing, they wouldn’t want to listen to me and wouldn’t trust me. But because I had such a great relationship with Michael, I knew that he’d be by my side and I’d be by his side. And it was exactly that, the entire time. It showed me that I really wanted to be involved in the entire process. Being able to jump from that into Anyone But You, which was such a different scale, a bigger studio film, and definitely not as dark, I got to kind of see both sides of filmmaking. I learned a lot, really fast.

I loved my experience on The Handmaid’s Tale (Sweeney played child bride Eden, a devout yet naive follower of the authoritarian regime). I love characters that you question. Like, how can you be so devoted to something that scares you? You don’t know the truth behind it, and in Immaculate, there’s so much that you question. Then, of course, the ending. The ending, it’s just kind of there, you know?

You kind of do the whole movie for the ending, and I could never get the ending (in which Sweeney’s Cecilia is covered in blood, in a very gory conclusion) out of my mind. I love playing characters that are super-raw and vulnerable. I prefer to wear no make-up on screen. In Immaculate, Eden, Echo Valley, Reality, all those films, I didn’t wear any make-up, and I loved it. I don’t like putting on concealer or foundation or anything like that when I don’t have to.

It’s because everybody just thinks of Cassie. She’s just such a pop-culture-type character, that’s in the zeitgeist of the world, and so that’s everybody’s first impression or thought when they think of me. But in reality, when you think of all the other projects that I’ve done in the last few years, none of them are like Cassie in any way.

You’re meant to be starring in a remake of Barbarella, which was announced back in 2022. What’s the latest news on that?

I was just in London and had a meeting to discuss the story and the script. I can’t say too much, but it’s really going to come together in a very, very fun and big way. It’s a long process. I don’t think people realise how long some things can take, but it’s gonna be worth the wait.

Is Barbarella another item on your bucket list?

Yes, it is. (Laughs) That’s what I’m saying! My thirties, I’ve really got to step it up!

Originally in the Summer 2025 issue of Empire. Sydney Sweeney was shot exclusively for Empire in Los Angeles on 6 March, 2025, by Art Streiber. Echo Valley is on Apple TV+ from 13 June.