The Take That star and X Factor judge revealed on Twitter tonight (February 19) that his wife Dawn is pregnant.
The couple, who married in 2000, are already parents to Daniel, 11, Emily, 9, and 3-year-old Daisy.
Barlow teased followers prior to his announcement, writing on the social networking site: "Gorgeous day in the Capital.I'm announcing some news on here tonight! (sic)"
He later tweeted: "I feel like I've built this news up to much.Hope you're not disappointed," before confirming: "My wife and I are expecting our 4th child #Anotherowngoal."
Barlow recently confirmed that he is in talks to return as a judge on The X Factor, though he has suggested in the past that his children take priority over the show.
> X Factor was for my children, says Gary Barlow