The Baywatch actress will be joining Simon Cowell, David Walliams and Alesha Dixon at auditions in London today (February 6).
The 39-year-old is to be a temporary replacement for Amanda Holden, who is recovering at home following the traumatic birth of her daughter Hollie on January 23.
Holden was said to be "fighting for life" after losing blood and requiring a number of transfusions in the wake of an emergency caesarean.
She is believed to have told Britain's Got Talent producers not to replace her with any more guest judges and will reportedly rejoin the panel in Edinburgh on February 11.
Myleene Klass and Samantha Womack were previously tipped to judge the London try-outs.