The Baywatch star made an official announcement on Twitter following rumours that he had been axed from the ITV contest after just one series.
"SO ITS OFFICIAL. I'M NOT COMING BACK TO BGT," he wrote. "thanks to everyone who supported me on my BGT days. Nothing but fond memories of the cast and crew and thanks to Simon Cowell."
Hasselhoff's departure follows Michael McIntyre's decision to quit the panel back in September.
Amanda Holden confirmed earlier this week that she would continue to judge Britiain's Got Talent next year, tweeting: "You will all have to be patient re BGT. I am doing it inc auditions!"
Former X Factor judge Dannii Minogue, EastEnders actress Samantha Womack and comedian David Walliams have all been recently linked to the show.