After crowning Paddy Doherty champion of Celebrity Big Brother, host Brian Dowling made the shock announcement that the Baywatch star will join 14 brand new housemates when the show launches on Friday.
Anderson was called to the Diary Room shortly after Doherty's interview, where she told Big Brother: "It's fun to be here."
She added: "I'm going to give them the ride of their lives, and leave a skidmark on every one of them."
Big Brother said that her appearance will be their "little secret", to which she replied: "Shhh!"
It is currently unclear whether Anderson will be a fully-fledged housemate or if her appearance will only be temporary.
Watch Pamela Anderson enter the Big Brother house below:
The actress had been rumoured to be entering the regular Big Brother house earlier this week, after originally being strongly linked to the celebrity edition, which concluded tonight.
Doherty walked away with the Celebrity Big Brother crown earlier tonight, beating out other favourites like Jedward, Kerry Katona and Amy Childs.
Dowling had already hinted at a surprise guest to be joining the regular series of Big Brother.
Watch Digital Spy's 'Are these the new Big Brother housemates?' video below:
Pamela Anderson recently sued her ex-boyfriend for $1 million (£666,667) over his failure to buy her a condo.
The new series of Big Brother begins Friday on Channel 5 at 9.30pm.
> Big Brother: Regular series to last 63 days, 14 housemate teasers