Rylan Clark-Neal made the announcement on spin-off show Big Brother’s Bit on the Side, while this series stars settled in for their first night in the house.
The 54-year-old former Liverpool player joined the house on Friday alongside a series of other men who will be setting the cat among the pigeons in the styled “Year of the Woman” in the Channel 5 compound.
Making the announcement, Rylan played John’s football-themed rap hit World In Motion and told the camera: “As you know, Friday night, the house will receive some gentlemen.
“Tonight, I can reveal that one of those very men, will be Liverpool legend and rap superstar John Barnes is going in the house!”
Former BB winner Kate Lawler then jumped from her seat and bust out some moves as the crowd cheered on the new addition to the compound.
John is the first male housemate confirmed after eight female celebrities entered the house tonight for the series launch.
Men will then enter the mix, but will not be allowed the right to vote at the beginning of their stay.
The compound has been given a feminine makeover as the show celebrates it being 100 years since women won the right to vote.