The couple met during the final run of Channel 4 reality show Big Brother last year. Gibson, who went on to win the series, confirmed the news on her Twitter page.
"Me & John r on a break," she wrote. "We r going to see if we can work things out. We may, we may not (sic)."
She added: "I will not be tweeting about our relationship again."
Last month, the Australian admitted that he was surprised the relationship had lasted, telling a magazine: "The more time we spend together the more I realise that we're opposites in every single way."
Gibson and Parton were due to appear together in her new three-part fly-on-the-wall series There's Something About Josie for Channel 5.
> BB Josie Gibson speaks about abortion
Watch our recent interview with Josie and John James below: