According to reports, Jamie's wife has given birth to their second child, after she was seen pushing a stroller in London this week.
The couple confirmed they were expecting their second baby last November, but they've keeping the pregnancy very private, and haven't made a formal announcement about their new arrival yet, including the gender or name of their second born.
Jamie, now one of the most coveted men in Hollywood, officially went off the market in 2013, when he married British actress Amelia Warner.
He is already a father to two-year-old daughter Dulcie, who was born in November 2013, only three days before he started shooting Fifty Shades of Grey.
The Hollywood heartthrob has since confessed how much he loves being a father. 'I love fatherhood', the actor told British Vogue in February last year. 'These last couple of years have been quite something. But we're enjoying it.'
In another interview with Stylist magazine, the father-of-two gushed about parenthood, saying: 'My father has delivered over 6,000 babies, my stepmother's an obstetrician gynecologist and I've been around a lot of baby talk in my life. But still, nothing actually prepares you. I hope I'm a good dad.
It's the most joyous thing imaginable. It's totally changed our lives but only for the positive.'
The Northern Irish actor has also spoken out about how much he dislikes some parents' attitude towards parenting, saying his advice to expecting parents is to just 'embrace it'.
'People are so f***ing down about having kids—in those early months when people are saying, 'Say goodbye to sleep.' Well, of course! You've got a baby!', he said.
'I was discouraged by people's attitude so it was refreshing when we occasionally met people who said, "It's the best thing, you're going to love it." I saw a pregnant friend the other night and I was like, "Embrace it! Don't listen to all the people who are down on it, because it's only good".'