Musicians Fleur East, James McVey, and actor Sair Khan all abstain from eating animal products - which has left TV bosses facing a 'crisis', according to The Sun.
As part of the show, contestants are forced to undergo 'Bushtucker Trials', where they have to eat animal parts including kangaroo testicles. But vegans are unlikely to take part in these activities.
A source told The Daily Star: "It could prove a bit tricky for bosses if they refuse to do the eating Bushtucker Trials.
"Fleur has already told bosses that she is strictly vegan and does not go near any animal products.
"It's certainly not ideal."
The three contestants are not the first vegans to enter the jungle: last year Stand-up comic - and vegan - Shappi Khorsandi revealed she was vegan shortly before the show started.
Writing in The Independent she said: "The last few months have marked a significant chapter in my life: I have started to come out to my friends and family as vegan."
But she ditched her plant-based diet for the show - which made her ill. "I had meat, and I was really, really physically sick, five times in one hour," she said. "It was horrible." She revealed the producers then made her vegan food parcels.
Cruelty to animals
I'm A Celebrity Get Me Out Of Here has faced criticism over its use and exploitation of animals. Various petitions have been set up calling for an end to animal use in the show.
Additionally, in 2014, wildlife expert Chris Packham (now working towards being 100 percent vegan) wrote an open letter to the show's producers. He said: "Please realize that this repugnantly gratuitous scenario also does immense harm to the establishment of a fundamental respect for life.
"All your younger viewers, those who are set to inherit a hugely impoverished planet probably without wild tigers, rhinos, elephants, are being taught that killing things for plain exploitative 'entertainment' is acceptable. I'm sorry, but that is a shame that I imagine neither of you will want to take to your graves, because I assure you that your grandchildren will not thank you for it."