The 39-year-old TV star – who already has son Max, six, and daughter Carey, three, with Julia – announced the arrival of their new baby girl on Twitter.
James – whose spot on ‘The Late Late Show’ was taken by Harry Styles for the night – wrote on the micro-blogging site: “Today we welcomed a beautiful baby daughter into the world. Both she and her mother are doing great. We can’t stop smiling. Thank you Harry for stepping in to host the show at 2 and a half hours notice! x x x.”
James revealed the baby’s sex at the 69th Primetime Emmy Awards in September, when he also explained that the couple were looking forward to the arrival of their child over the Christmas period.
He shared: “She’ll be arriving Christmas – we’re very excited. It will be great, lovely. We’re having a little girl, it’s going to be terrific.”
And James joked that he was doing his best to satisfy his wife’s food cravings during the event.
The British TV star said: “I’m here with my wife and she’s five months pregnant, so it’s mostly just thinking of places that I could hide snacks. Because she’s gonna get hungry every seven minutes … It’s just I will face the wrath if she’s not fed.”
James and Julia have been married since September 2012, and have relocated to the US since the popular presenter took over ‘The Late Late Show’ in 2015.
James previously revealed the circumstances surrounding the start of his relationship with Julia, admitting she wasn’t aware of who he was when they first fell in love.
Speaking in 2016, he said: “I could never understand when I watch romantic comedies the notion that for some reason unattractive or heavy people don’t fall in love.
“If they do, it’s in some odd, kooky, roundabout way – and it’s not. It’s exactly the same. I met my wife; she barely owned a television and worked for Save the Children. We sat down one night and we fell in love and that was it.”