Margot Robbie and Tom Ackerley are "so happy" as first-time parents.

The couple - who married in 2016 - welcomed their son into the world earlier this month and because they waited "a long time" to start their family, they were in shock when he actually arrived and are enjoying some quiet time at home.

A source told People: "They waited a long time to get pregnant, so it was almost unbelievable when the baby actually arrived. They’ve both been settling into being parents.

"They’re homebodies so it’s been lovely to spend the time just them, at home with him. They’re so happy."

Neither the 'Barbie' star nor her husband have disclosed the news of their baby publicly, and as such, neither his name nor specific birthdate are known around the world yet.

Friends and family of the loved-up couple - who met in 2013 on the set of the World War II drama 'Suite Francaise' - had made a concerted effort to keep the news of the baby's arrival under wraps.

Meanwhile, Margot previously described herself as the "ultimate single gal" before meeting Tom.

But the 'Wolf of Wall Street' actress admitted that the film producer has changed her outlook entirely.

Reflecting on the evolution of their romance, Margot told Vogue magazine: "I was the ultimate single gal. The idea of relationships made me want to vomit.

"And then this crept up on me. We were friends for so long. 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'. And then it happened, and I was like, of course we're together."

The Hollywood star admitted that their relationship just "makes so much sense".

Margot - who married Tom in a private ceremony in Byron Bay in Australia - explained: "This makes so much sense, the way nothing has ever made sense before."