All About Oli Green, Sienna Miller’s Fiancé

THE RUNDOWN

• Sienna Miller and Oli Green have been linked since 2022.
• “I didn’t expect to take it seriously and then quite quickly, I fell in love,” Miller previously shared.
• The couple has one daughter together, and in May 2026, she announced that they recently welcomed their second child.

Sienna Miller is in a relationship with Oli Green, whom she’s been linked to since winter 2022. They’ve even started a family together. In June 2026, she revealed their engagement.

Before Green, Miller dated fellow actor Tom Sturridge, and together they welcomed their daughter, Marlowe Sturridge, in 2012. In her June 2024 cover story for Harper’s Bazaar UK, she revealed that she and Tom are still friends and work together to co-parent their daughter.

“She’s magical,” Miller said of Marlowe. “It’s amazing when you have these little people and there’s a universe inside their heads. Her father is incredibly bright, but also very deep. And she’s straddling this kind of comedy-jokester part of me and this intensity that comes from his brilliant mind.”

Now, Miller has a daughter with Green—and in December 2025, she announced that she was pregnant with their second child. Months later, in May 2026, she confirmed their newborn’s recent arrival. Ahead, everything to know about actor Oli Green and his relationship with Sienna Miller.

Miller isn’t the only actor in the relationship. Green has starred in Bridget Jones: Mad About the Boy, The Crown, A Good Person, and Lift.

According to his IMDb page, his first gig was in 2019 for John Eatherly’s music video for “Burnout.” Model and actress Kaia Gerber played his love interest.

It’s unclear exactly when the actor couple started dating, but they sparked romance rumors in early February 2022 when they were spotted at Madison Square Garden at the New York Knicks vs. Memphis Grizzlies game. Photos came out of them walking together, with Green’s hand on Miller’s shoulder.

That March, they were seen together again. Paparazzi photographed them in the backseat of a car, reportedly leaving the BAFTA Awards and heading to an after-party.

In January 2024, People reported that the couple welcomed their first child together, a girl.

People first reported Miller’s pregnancy in August 2023.

While around 32 weeks pregnant, Miller and Green went on a “babymoon,” something she later told The Times. She shared that she had an “easy pregnancy” and was “up for traveling far.” They decided to go to the Maldives, and Miller reminisced on the experience that she had, like the resort staff welcoming her with a “Welcome to your babymoon” sign and a baby-shaped cake.

This was Miller and Green’s first trip together as a couple.

“When Oli and I were preparing for the trip we realized that we’d never actually been on holiday, just the two of us, in our entire relationship. So it was really magical to have that time together, thinking about each other and the baby that was about to arrive,” she concluded.

She previously shared with ELLE UK in 2022 that she felt “pressure...[about] kids, and should I have more, and why haven’t I, and all of that, which is a really loud noise. Biology is incredibly cruel on women in that decade—that’s the headline, or it certainly was for me. 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.”

When speaking with Harper’s Bazaar UK, Miller got personal about her mostly private relationship with Green. She explained how, after first meeting him at a Halloween party, she didn’t see herself falling for the 29-year-old actor, who is 15 years younger than her.

“I didn’t expect to take it seriously and then quite quickly, I fell in love,” she recalled. “I wasn’t like, ‘I’m gonna get a younger boyfriend.’ It was more, ‘Fuck! Why are you young? That’s so annoying.’”

However, their relationship works despite the age gap.

“There is a difference in the way that generation of men respect women. It’s specific to him, he is very wise and well-adjusted, but I do believe it’s also that generation. They have grown up with a slightly more level playing field. I see it in his female friends as well as in the men,” Miller explained.

Miller and Green walked their first carpet together as a couple in March at the Vanity Fair Oscar Party. The actress wore a champagne-colored satin dress with a cutout at the waist and crystals embroidered on the bodice. Green posed next to her in a navy-blue pinstripe suit and tie.

Green supported Miller at the premiere of her film Horizon: An American Saga at Cannes Film Festival. The actress made it a family affair, also bringing her daughter Marlowe Sturridge and her mother, Josephine Miller. The four of them posed for photos together on the red carpet.

At the end of the night, Miller, Green, and Sturridge made their way to a Horizon: An American Saga after-party at Lucia Cannes.

In April 2023, they went to the Prince’s Trust Gala together. Miller wore a sheer nude dress with intricate shimmering embellishments and a pink tulle cape spilling down her back. Green, meanwhile, wore a navy-blue pinstripe suit, leaving his white shirt underneath partially unbuttoned.

In December 2025, Miller announced that she and Green were expecting their second child when she debuted her baby bump at The Fashion Awards in London. For the occasion, the couple walked the red carpet together, and she wore a white sheer gown.

Months later, in May 2026, Miller revealed that she and Green welcomed their second child during an interview with E!. “It’s happened,” she told the outlet. “I have a tiny baby next door.”

She also spoke candidly about adjusting to life as a family of five, saying, “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.”

On June 9, People confirmed that Miller and Green were engaged after four years together. The news came days after Miller sparked speculation when she was photographed in Spain wearing a diamond ring on her left hand.