The "Barbie" star and the film producer have welcomed their first child, a baby boy, People magazine reported on Saturday.
According to the Daily Mail, the pair's son was born on Oct. 17. The outlet noted that Robbie went into labor two weeks ago, shortly ahead of her due date.
Neither the "Birds of Prey" star nor Ackerley has publicly announced the birth of their child.
HuffPost has reached out to Robbie's reps for comment.
The Australian actor and Ackerley tied the knot in December 2016 after meeting on the set of 2014's "Suite Française." Robbie starred in the war drama, while Ackerley served as an assistant director.
Robbie gushed about her relationship with Ackerley while speaking with Vogue in 2016.
"We were friends for so long," she said at the time. "I was always in love with him, but I thought, 'Oh, he would never love me back. Don't make it weird, Margot. Don't be stupid and tell him that you like him.'"