Dominic West, Jeremy Irons and Dame Vivienne Westwood are shown cuddling up to a little pig as part of an effort to persuade the public to buy meat from pigs raised in more humane conditions.
The #TurnYourNoseUp campaign seeks to highlight the plight of pigs in intensive rearing units - or "factories".
A video shows Miranda Richardson, Richard E Grant, Sadie Frost and Jon Snow visibly horrified as they are shown footage of pigs in small pens and cramped conditions.
Batman actor Jeremy said: "I eat meat, but for me to eat the meat of animals that have been raised inhumanely, cruelly, somehow seems to taint my own humanity."
Newsreader Jon highlighted the dangers of antibiotic resistance, as livestock were routinely dosed with antibiotics. He said: "Antibiotics overuse is causing antibiotic-resistant diseases in pigs that can then pass to humans."
Celebrities including Stephen Fry, Sting, Rupert Everett, Moby, Jools Holland, Joanna Lumley, and Sir Roger Moore will post selfies on Thursday of them "turning their noses up".
Others to back the campaign include Jamie Oliver, Stella and Sir Paul McCartney, Hugh Grant and Lily Allen. Black-and-white portraits by fashion photographer Clive Arrowsmith show Jeremy staring down the snout of a pig, while Hugh and Rupert cradle the pig in their arms.
Tracy Worcester, founder of Farms Not Factories, said: "Our message is simple, we want to help bring an end to this dangerous, inhumane system and encourage the public to only buy pork from high welfare farms.
"Vote for real farming over factory farming by buying pork with the labels RSPCA assured, outdoor bred, free range or best of all, organic."