The 46-year-old chef, famous for co-hosting the BBC One reality show with Gregg Wallace, had been married to Jessica for four years after living together since 2001.
His spokesman said in a statement: "John has always preferred to keep his personal life private and at this time we hope that people respect this."
They share two children together, 7-year-old Jonah and 5-year-old Lulu, while Torode has two other children - 14-year-old Marselle and 12-year-old Casper - from a previous relationship.
A supposed friend told RTÉ: "It is very sad, particularly considering they have young children. They were such a nice couple."
It is believed that Torode moved out of their £1.2 million family home in south-west London during the Christmas holidays.