A spokesperson for Celebrity Big Brother said: "Roxanne has chose to leave the BB House".
The former Emmerdale star, 35, was seen threatening to leave the house during Friday night's live eviction which saw her friend, Ben Jardine, evicted following a house vote. She also said she was "in pain all night".
It was later revealed that Roxanne had chose to leave after Ben Jardine's eviction on Friday, having spent two days reflecting on recent incidents.
A Celebrity Big Brother spokesman told the BBC: "Roxanne has chose to leave the Big Brother house".
"I'm feeling really lost and uncomfortable", she added.
The allegations have sparked over 11,000 Ofcom complaints and thousands taking to Twitter to claim Pallett invented the allegation in an attempt to get Thomas evicted - who is now the bookies favourite to win the series.
Although officially contract matters aren't commented on, former CBB housemate Angie Bowie previously claimed walkers can still get some of their fee.
Roxanne claimed on the show that Ryan had intentionally tried to hurt her, labelling him a "woman beater".
After the incident, Pallett complained to the show's producers about Thomas's behaviour and he was issued him with a formal warning for physical contact by Big Brother bosses. I have never felt an impact and a repetition of fists going into my ribs, in my life'.
In a statement, Channel 5 said: "Roxanne has made a decision to leave the BB House".
"We both know and Roxanne knows there was no malice, hurt or anger in anything I did during this time".
Celebrity Big Brother continues at 9PM daily on Channel 5.
Dan Osborne concurred, saying: 'He has just admitted he's had a problem with her from years ago, and to me you don't hit someone like that if you don't like them. "I promise you've got it wrong".
Pallett had initially told Big Brother that she was upset by the altercation while in tears, and she asked to sleep in a separate bedroom.