‘I don’t have to be the biggest movie star in the world’: Sienna Miller on Hollywood, being a mother and her next big role

As one of Hollywood’s most stylish celebrities, Sienna Miller is used to the spotlight. Here, the 42-year-old opens up about fame - and the birth of her second baby last year.

Picture: AFP

As one of Hollywood’s most stylish celebrities, Sienna Miller is used to the spotlight. But in recent years, the 42-year-old British actor confesses, she is much less interested in fame. Ahead of her role in US Civil War era Horizon: An American Saga – a passion project spanning multiple movies for director, writer and star Kevin Costner – Miller reveals a recent “mic-drop” career moment, and why she and her partner, actor and model Oli Green, left New York and moved back to London to raise their family.

Stellar: Kevin Costner called to ask you to join him on his epic Western film series Horizon: An American Saga. How did that feel?

Sienna Miller: It was extraordinary. I still haven’t asked [him why]. And I don’t ask – I just say “thank you”. I think he had watched my stuff, but it was very out of the blue. I grew up in the ’90s, so Kevin Costner to me was God. I had rabbits called Two Socks and Cisco because Dances With Wolves [the 1990 movie Costner directed and starred in, featuring a wolf called Two Socks and a horse called Cisco] was my favourite film. It was really like, “Kevin Costner wants to talk to you? This is a joke …” He was charming, and he told me about the project and then said, “Will you go west with me?” And I was like, “I’ll go to Mars with you.” Very out of the blue.

Sienna Miller at the 81st Venice International Film Festival at Palazzo del Cinema in Italy over the weekend. Picture: Getty Images

Picture: Getty Images

With Kevin Costner, right, on the red carpet in Venice. Picture: AFP

Stellar: Had you ever met before?

Sienna Miller: No. Never met before. No, only in my dreams. F*ck, that’s gonna sound awful in print. It was a joke!

Stellar: Your character, Frances Kittredge, is very much a mother first. How did that factor into your thinking about her?

Sienna Miller: Well, it’s impossible to play a mother with children in a situation that precarious – knowing it’s based on history, there’s nothing that’s been embellished – and not relate it to your own experience. We’re so sensitive these days about our own psychology, and “How do I feel today?” You make a film like this, and you’re like, “Shut up, get on with it.” We have it so easy. Life is always complicated, but for the mothers [then] it was astoundingly difficult, and painful to watch and painful to shoot, because you can’t help but make that personal. So I’d have my daughter [Marlowe, 12] with me and hug her very tight at night.

Stellar: You were pregnant with your second child [a baby girl, whose birth was confirmed in January this year] during the shoot of the second chapter of Horizon. How was that?

Sienna Miller: I only told Kevin … It was early enough that I wasn’t showing. And actually the corset goes [around your waist]. You can have a little bump underneath. And the big skirt – you could hide it, it was fine.

Picture: Karwai Tang/WireImage

What is one moment from the Utah set that you will never forget?

Oh, there are so many. Every day something happened, whether it was a dust storm or … it’s hard to not be blown away by the majesty of the landscape. And the beauty of the sets and the costumes and the way that the light changes, and there are just horses and cowboys. You can’t believe this set, it was everything I dreamt of when I dreamt of making movies.

For more from Stellar, listen to the latest episode of the podcast, Something To Talk About:

You recently moved back to London from New York. What made you want to leave the Big Apple?

I’d done it by that point. And I feel like the pandemic affected my experience of what New York was. It’s so the epicentre of culture as a city, but culture now is a very different thing to what it was when I moved there. And it’s very TikTok and a lot of people filming themselves. London for me, with young children, it’s a better quality of life. I can let my dogs off the leash without being yelled at. Little things that as you get older start to get really irritating. I don’t want to be told what to do all the time. So I’m happy to be back in London.

Have things changed in the film business since you had your first child?

Listen, in my experience, I was always allowed to have my daughter with me at work. And I like to be with my family. And my own experience of motherhood 12 years later is completely different. I’m a very different person. People often have lots to say about having babies in your 40s as women, but I can’t advocate for it more. I feel very lucky. But everybody makes it work. I mean, Foxcatcher, I was breastfeeding on that set [in 2014]. It was accepted.

Sienna Miller and Kevin Costner in Cannes for a screening of Horizon: An American Saga. Picture: AFP

Sienna Miller, centre, with Oli Green and her daughter, Marlowe Sturridge. Picture: Getty Images

Oli Green and Sienna Miller at Anna Wintour's pre-Met Gala dinner in May. Picture: Gotham/GC Images

How about now? What has it been like being both an actor and a mum to a new baby?

I’ve just finished maternity leave. My baby is eight months old. It’s great, since this whole focus on the female experience in Hollywood, I can take my baby everywhere and they’ll have to stop filming for me. I’m still breastfeeding. I’ve been pumping and sending milk back to the hotel, and you just make it work. I’m equally fulfilled by both things. And I’m lucky that I’m in a job where I can have my baby at work.

You appeared in the final season of Curb Your Enthusiasm. What was it like working with Larry David?

I mean, I can die a happy woman now. It’s a mic-drop moment. I’ve ticked every box. That was a dream come true to be on that show. It’s amazing. And the best thing about Larry David is that he just cracks up laughing the entire time. I mean, we didn’t get through one take … It’s all improvised, which was terrifying.

A pregnant Sienna Miller atVogue World: London 2023 last September. Picture: Mike Marsland/WireImage

You’ve been an actor for more than two decades now. How do you reflect on your career?

I don’t think I’ve ever felt more personally fulfilled. And that’s wonderful, because I can just enjoy the work without any neuroses. I do want to strategise about getting to a place where I have enough bankability to work with Yorgos Lanthimos and Martin Scorsese. I want to be in those films with these auteur directors, to name a couple on the extensive list that I have.

I don’t have to be the biggest movie star in the world. I love that I get to keep working. I know I will work the rest of my life. I get to do a play, I’ve got a beautiful new baby. Yeah, very happy.

Horizon: An American Saga is streaming on Stan. Read the full interview with Sienna Miller inside the latest issue of Stellar. For more from Stellar, click here.

Originally published as ‘I don’t have to be the biggest movie star in the world’: Sienna Miller on Hollywood, being a mother and her next big role