Sienna Miller Welcomes Baby No. 3 With Oli Green

Sienna Miller is a mom of three. The actress confirmed the arrival of her newest baby during an interview with E! News on May 11, delivering the news in the most disarmingly honest way possible.

“It’s happened. I have a tiny baby next door,” she told E!’s Will Marfuggi, barely containing her joy. “It feels like stringing sentences together is a bit challenging. I’m on very little sleep but I’m madly in love with my baby.”

That’s about all she shared — no name, no sex, no birth date. Just a new mom running on fumes and pure adoration, which honestly tracks.

The baby is Miller’s second child with boyfriend Oli Green, 29, and her third overall. The couple are already parents to a daughter — whose name they’ve kept private — born in January 2024. Miller is also mom to Marlowe, 13, from her relationship with actor Tom Sturridge.

How the Pregnancy Was Revealed

Miller first revealed she was expecting back in December 2025, in the most fashion-forward way imaginable. She walked the blue carpet at the British Fashion Awards at Royal Albert Hall in a sheer white strapless Givenchy gown — plunging bra cups, a floor-grazing see-through skirt, pearl statement earrings, and a very visible baby bump. Green was right beside her in a pinstripe suit, looking every bit the proud partner.

Vogue’s official Instagram account made it official that night, posting: “@siennathing is pregnant! The star revealed she is expecting her second child at 43 with partner Oli Green at the #BritishFashionAwards this evening, in a @givenchy dress and all.”

The announcement came just over a year after their first daughter arrived — a pace that Miller herself has been refreshingly candid about navigating. “Having had a baby at 29, and then having a baby at 42, and now 44, it’s so much easier when you don’t have the conflict of feeling scattered,” she told Glamour. “Life is in a more grounded space. I think the 30s are chaos.”

She’s also been unapologetic about pushing back on the idea that there’s anything remarkable about having children in your 40s. “We don’t judge men who are having kids in their 80s,” she said. “Why on earth is there any sort of narrative?”

The Road to Three Kids

Getting here wasn’t without its anxieties. Back in 2022, Miller opened up to Elle UK about freezing her eggs at 40, describing the pressure she’d felt about having more children as almost consuming. “Biology is incredibly cruel on women in that decade — that’s the headline, or it certainly was for me,” she said. “Having been really focused on the need to have another baby, I’m just like, if it happens, it happens. That kind of existential threat has dissipated.”

That same year, she told British Vogue just how deeply she’d wanted this life. “I imagined that I would be married with three kids, being a great mum,” she said. “There was a lot of anxiety. Relationships hadn’t worked out.” Three kids later, she got there.

Miller and Green met at a party in 2021. She’s been candid about the fact that she didn’t take their connection seriously at first — partly because of the 14-year age gap. “I wasn’t like, ‘I’m gonna get a younger boyfriend,’” she told Harper’s Bazaar in 2024. “It was more, ‘F***! Why are you young? That’s so annoying.’” Green, for his part, reportedly had to work to convince her to go on a date at all.

But she fell, and fast. “I didn’t expect to take it seriously,” she recalled. “And then quite quickly, I fell in love.” On their age difference, she’s become one of its most thoughtful advocates: “There is a difference in the way that generation of men respect women. They have grown up with a slightly more level playing field.” Most recently, she told Grazia that the idea of an older woman with a younger man is “still fetishized rather than normalized” — a disparity, she said, she’d “love to see disappear.”

Back to Work — With a Baby Next Door

Miller was doing press for her new project, Jack Ryan: Ghost War, when she dropped the baby news. In the Prime Video series — arriving May 20 — she plays MI6 officer Emma Marlowe, a character she described as “incredibly unapologetic, incredibly tough and bold and brave and pretty funny and dry and very cool.” Playing someone so different from her previous roles, she said, was “thrilling.”

Her costar had nothing but glowing things to say. “I don’t know if this movie happens if Sienna said no,” he told E!. “I just knew we’d be so lucky to not only get who I think is one of the best actors working but I didn’t know she was one of the funniest people on planet Earth. To be in these pressure cooker situations doing stunts but wiping tears of laughter away right before you do them was extremely helpful.”

There’s one person, though, who remains thoroughly unimpressed by all of it: Marlowe. Miller admitted her 13-year-old “couldn’t be less interested in my career if I tried.” But she’s holding out hope that the character name might do the trick. “I thought people calling me ‘Agent Marlowe’ would hook her,” she laughed. “So maybe she’ll finally watch a film of mine.”