Host Emma Willis introduced 13 new celebrity contestants as the series returned to Channel 5, promising to keep them guessing with a string of surprises.
Former 'Coronation Street' stars Bruce Jones and Vicky Entwistle - who played Les and Janice Battersby on the ITV soap - entered the house together as one housemate, while dancer Louie Spence proved popular with the crowd as he made his way inside the Elstree compound.
Model Sophie Anderton looks set to cause fireworks, having previously starred in 'I'm A Celebrity… Get Me Out Of Here!', where she came to blows with Natalie Appleton.
The names of the housemates had been kept under wraps until launch night, but speculation that teen bride and singer Courtney Stodden would appear proved to be correct.
The 18-year-old model, who rose to fame when she married 53-year-old actor Doug Hutchinson when she was just 16, is rumoured to have been drafted in to replace Whitney Houston's daughter Bobbi Kirstina Brown, who is reported to have pulled out of the competition earlier this week.
Others who entered the house include Richard Breen, best known as Abz Love from 90s boyband 5ive; 'Geordie Shore' personality Charlotte Crosby; Dustin Diamond, who played Screech in television show 'Saved By the Bell'; and Lauren Harries, who became famous as a child prodigy before undergoing a sex change.
Completing the line-up is little-known celebrity botox doctor Danielle Marr.
A statement said: "This series will be loaded with countless twists, turns and tough tasks to keep our celebrities on their toes."
The house has been given a celebrity make-over after the regular series of 'Big Brother' ended earlier this week.
The new celebrity housemates will be under constant surveillance from 27 remote-controlled cameras, 12 fixed cameras, five manned cameras, 10 infra-red cameras, a tower cam and 57 camera mirrors strategically positioned across the house.
'Celebrity Big Brother' continues on Friday night with 'The Big Twist' at 9pm on Channel 5.