Who is Oli Green? Details explored as Sienna Miller set to welcome her third baby with him

Oli Green is an actor and model, but his IMDb page also lists him as a producer. He is making headlines recently after his girlfriend, Sienna Miller, gained attention at the 2025 Fashion Awards at the Royal Albert Hall in London on December 1 after showing off her baby bump on the red carpet. 

The 43-year-old actress turned heads at the London event in a sheer white Givenchy gown with a bustier-like neckline that showed off her growing baby bump. Oli was also in attendance and the soon-to-be new mom and dad posed for photos together. 

It's going to be Sienna Miller's third baby, but her second with Oli Green. The actress has a child, her eldest, with ex Tom Sturridge, with whom she was sometime from 2011 to 2015. 

Exploring Oli Green's career and life with Sienna Miller amid their recent pregnancy news

Born on January 21, 1997, Oli Green works on television, film, and the fashion industry as an actor, producer, and model. He's been acting since 2020, according to his IMDb page. Green snagged his first acting role as a guest in the long-running soap opera The Bold and the Beautiful and then in the TV series The Mosquito Coast. 

He also appeared in five more projects in TV and film so far, including The Crown, Lift, A Good Person, and more recently in Bridget Jones: Mad About the Boy. Green played Russ, the checkout guy, in the romantic comedy starring Renée Zellweger. Oli Green's biggest acting role so far will be in Kevin Costner's The Grey House, which premiered at the Monte-Carlo Television Festival in June 2024.

The Western historical spy miniseries will be streaming on Prime Video in the US in early 2026. Oli Green appears in five of the show's seven episodes as Paul Revere. IMDb also lists him as one of the producers for the French short film Marion. 

But before he burst into the acting scene, Oli Green worked as a model for various brands like GAP and Burberry. He also shot campaigns for Massimo Dutti, among others, and posed with Sienna Miller for an ad campaign for the fashion company Frame earlier this year. They were the first celebrity couple to model for Frame. 

And speaking of the couple, they first met in 2021 at a Halloween party thrown by their mutual friend. She told Vogue in 2024 that it wasn't love at first sight, but they did kiss the night they met. Sienna Miller also addressed her 14-year age gap with Oli Green, saying that she almost wrote off the idea of them being together because of their age gap. 

However, the actor reportedly "worked hard to persuade" her to go out for a drink with him. They've been together ever since, and she told Vogue that there has been "nothing by love and joy" in their relationship since they first met. They made their first red carpet appearance together in March 2022, per US Weekly, and she gave birth to their first baby over a year later. 

Sienna Miller and Oli Green keep their family life mostly out of the spotlight, but she did share the reaction of her eldest daughter Marlowe, whom she co-parents with Tom Sturridge, about her first baby with Oli Green. She told E! News in 2024 that while having a new baby was initially "a lot" for Marlowe, the baby is already idolizing her big sister. Now, with the actress's latest pregnancy news, Marlowe will have a new sister to welcome into the family. 

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