Paul Hollywood and his wife Alex are separating after nearly 20 years of marriage.
The Great British Bake Off judge and his wife, who is a chef, said in a joint statement: "It is with sadness that we have decided to separate.
"Our focus continues to be the happiness of our son... we ask the press and public to allow us privacy during this very difficult time."
They previously separated in 2013 when the TV baker admitted having an affair.
Hollywood confessed to having had a relationship with Marcela Valladolid, his co-star on the US version of Bake Off, which was axed after one series due to poor ratings.
He and his wife got back together a few months later and he described the incident as "the biggest mistake of my life" in an interview with BBC Radio 5 live.
Speaking at the time, he said he "was shocked about the whole thing kicking off the way it did... but I deserved it and I've taken it", adding: "It was my punishment."
Hollywood will return as a judge for the second series of Channel 4's The Great British Bake Off next year, having moved with the show when it went to Channel 4 from its original home on the BBC last year.
He was head baker at a number of hotels before finding TV fame, launching his own bread firm and writing recipe books.