The mother-of-five hit back via Twitter following an allegation on Friday that she'd announced in front of clubbers in London that her marriage was over.
An angry Katie tweeted: "Sorry to shatter your illusions but you couldn't be further from the truth! I love him and not splitting up #lies
"From the horses mouth me and Kieran are 100 %together not splitting up we are very happy and very much in love leave our relationship alone (sic)."
Katie and Kieran married in January 2013 after a whirlwind romance and seemed to be living the fairytale until the following year, when Katie discovered Kieran had been cheating on her with her best friend Jane Pountney.
Former glamour model Katie was pregnant with Kieran's second child at the time.
A heartbroken Katie initially vowed to divorce Kieran before taking him back and standing by him as he underwent therapy for sex addiction.
Since then she's been pretty vocal when it comes to discussing Kieran's betrayal and how she found the strength to fight for their marriage, although she has warned she will forgive but not forget.
Katie detailed Kieran's affair in her autobiography Reborn, released in October, where she gave graphic and never before heard information.
But rehashing that affair for the book brought back all the emotions of the time, which led Katie to temporarily leave her role as a regular panellist on Loose Women in order to focus on her marriage and family.
"My heart is shattered, it's broken. It's nowhere near healed," she admitted in October.
"We had therapy and I thought I was OK. The past two weeks I've been on my book tour and it's opened up some wounds. It's been awful. I thought I'd dealt with it."
"My heart is still healing. Someone said it takes five years to heal a broken heart. Is that true? I want to clarify me and Kieran are absolutely fine. We are not splitting, nothing like that. It's just been hard emotionally for us," she added.
"It's horrible for both of us. I'm always like, 'it's fine' and move on to the next thing... It's a relief to me to admit I'm not as strong as people think. Enough is enough. I have to let my barriers down."
Katie will return to Loose Women on 2 December.