Meet Sienna Miller’s 29-year-old boyfriend and baby daddy, Oli Green – a model and actor

Sienna Miller is officially a mother of three. The G.I Joe actress recently confirmed that she welcomed her second child with her boyfriend, Oli Green. The couple has been romantically linked since February 2022. In January 2024, media reports confirmed that they had welcomed a baby girl.

Miller first revealed her third pregnancy when she and Green attended The Fashion Awards 2025 at London’s Royal Albert Hall, wearing a see-through Givenchy gown that showed off her baby bump. In a recent interview with E!, she revealed that she and Green had since welcomed the baby. “It’s happened. I have a tiny baby next door,” she said. “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.”

Miller, who is set to star in the upcoming film Tom Clancy’s Jack Ryan: Ghost War, shares her firstborn child, daughter Marlowe, with ex-boyfriend Tom Sturridge, whom she dated from 2011 to 2015.

So who is Oli Green, Miller’s long-time boyfriend with whom she shares two kids?

Oli Green is an actor and model

Born in Los Angeles in 1997 to Jonathan Green and Alison Ross Green, Oli has strong links to the art world through his parents, according to British media. His father is the son of an art dealer and gallerist, while his mum has worked at Sotheby’s in New York and Serpentine Galleries, and is now a development adviser at Frieze Masters, per her LinkedIn.

But Oli seems to be walking a different path. Like Miller, Green works in the entertainment industry as an actor after studying at the Strasberg Theatre & Film Institute in New York.

Aside from acting, Green has worked as a model for several years, appearing in campaigns for brands like Gap, Massimo Dutti, Burberry and more. The model-turned-actor has shot campaigns with some of the industry’s biggest names including Cara Delevingne and Suki Waterhouse, too.