The 11 Celebrity Big Brother tenants have spent their first night together since entering the Channel 4 show.
Contestants include Michael Jackson's brother Jermaine, A-Team star Dirk Benedict, director Ken Russell and Bollywood actress Shilpa Shetty.
Donny Tourette, of punk band The Towers of London, exchanged insults with the crowd on opening night, while model Danielle Lloyd was met with boos.
Some of the press have already labelled the line-up "nobodies" and "wrinklies".
Votes from viewers will decide which stars are ejected during the series, which is expected to last a month.
Contestants also include former S Club 7 singer Jo O'Meara, ex-Steps star Ian "H" Watkins, Kenny Everett Show actress Cleo Rocos and newspaper columnist Carole Malone.
Lloyd, 23, lost her Miss Great Britain title after posing for Playboy and starting a relationship with footballer Teddy Sheringham, who had been one of the judges.
Russell, who at 79 is comfortably the oldest of the contestants, entered the house wearing a garish waistcoat. The director of Women in Love and The Devils says he is a Big Brother fan.
Former pop star-turned-dog breeder O'Meara said hello to the cheering crowd and told presenter Davina McCall: "I am absolutely terrified, I can't tell you how scared I am."
Sayer entered the house suggesting appearing on the show was "something to do in January in the rain".
The most dramatic entrance was made by Benedict, who also starred in Battlestar Galactica, as he arrived in a replica A-Team van, smoking a large cigar to cheers from the crowds.
Each celebrity will nominate a charity and the money raised during the voting process will be split equally between the organisations.
In last year's show, eventual winner Chantelle Houghton had been "planted" as a non-celebrity but proved the most popular contestant.
She went on to marry one of her fellow participants - Samuel Preston, the singer with musical group The Ordinary Boys - and was also signed up as a TV presenter.
Another highlight from last year was the MP George Galloway pretending to be a cat, licking milk from the cupped hands of actress Rula Lenska.