Sienna Miller has announced that she’s pregnant with baby number three. The actress looked stunning as she unveiled her growing bump on the red carpet of the Fashion Awards 2025, where she wowed in a white flowing Givenchy gown alongside her boyfriend Oli Green.
From the pages of magazines to Hollywood premieres, we’re well-acquainted with Sienna’s public profile - but what about her private life? The star has regularly opened up over the years about everything from her desire to build a family to relationships that didn’t work out.
To celebrate her latest happy news, here’s all you need to know about the glowing mum-to-be…
© Gareth Cattermole/Getty Images fHow old is Sienna Miller?
Sienna, who was born on 28th December 1981, is 43 years old. The actress - who rose to prominence for her roles in the likes of Anatomy of a Scandal, American Sniper, Layer Cake - will turn 44 later this month.
In 2022, Sienna opened up to ELLE UK about the pressure of the 30-something body clock on fertility. "Biology is incredibly cruel on women in that decade - that's the headline, or it certainly was for me," she said. "Then I got to 40 and I froze some eggs. 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."
In another 2022 interview with British Vogue, Sienna admitted to feeling "sad" during the same decade about failing to find the one before she met Oli. "There was a lot of anxiety," she shared. "Relationships hadn't worked out – I imagined that I would be married with three kids, being a great mum." She has previously dated Jude Law, Balthazar Getty and Lucas Zwirner.
How old is Sienna Miller’s boyfriend?
Following much discussion, Sienna has previously opened up about her ‘age gap’ relationship with her partner Oli. She has been dating the actor and model since 2021, with the couple having met at a Halloween party thrown by a mutual friend that same autumn.
Sienna has revealed that she was initially concerned about their approximately 15-year age difference, given that Oli was born in 1997 and is 28 years old. "I was like, 'this is absurd. This will not go anywhere,'" she told British Vogue in 2023. “He worked hard to persuade me to go out for a drink with him.”
© WireImageReports that the couple were dating first surfaced in early 2022 when they were spotted departing the BAFTA Film Awards together. However, that March, they confirmed their romance on the red carpet at the Vanity Fair Oscars afterparty.
Oli, just like Sienna, is an actor - having starred in Bridget Jones: Mad About The Boy and two episodes of The Crown. He is also a model, posing for campaigns with brands such as Burberry and Gap.
Sienna Miller's other children
Sienna has a 13-year-old daughter, called Marlowe, with her former partner Tom Sturridge. She dated the actor between 2011 and 2015, and the pair have continued to amicably co-parent ever since they parted ways.
In 2019, she told ELLE UK that they remained on such good terms that he sometimes stayed over. "He’s at the house and he’s going to stay there tonight," she told the interviewer. "It’s not like there’s a structure for custody. We make it work. It’s not conventional."
The star also has a daughter, aged 23 months, with her current boyfriend, Oli. They welcomed her in January 2024, with photos of the couple pushing a pram confirming her arrival. However, they have yet to publicly reveal the little girl’s name.
