It has been widely reported in the tabloid press that the TV personality has jetted to the US to wed her boyfriend, who she announced her engagement to in April.
The couple obtained a licence in Clark County, Nevada, and have one year to marry before it expires, PA Media reported.
Katie and Peter married in 2005 after meeting on I’m A Celebrity… Get Me Out Of Here! and they had two children, son Junior and daughter Princess together.
Their relationship was documented by their joint reality shows, but they split in 2009.
She married cage fighter Alex in Las Vegas in 2010 before divorcing a year later.
Katie then married third husband Kieran in 2013, and while they split in 2018 after renewing their vows for a third time, their divorce was only finalised earlier this year.
The couple also share son Jett and daughter Bunny.
Katie and Carl jetted to Las Vegas earlier this week following her recent stint in The Priory, and have been documenting their trip on Instagram.
The former Loose Women panellist is currently awaiting sentencing after pleading guilty to drink-driving following a car crash in September.
After her arrest, Katie was charged with driving while unfit to drive through drink, using a motor vehicle in a public place without third party insurance and driving while disqualified.
Sentencing was postponed until 15 December on the condition that Katie undergo treatment, not commit any further offences, and be banned from driving in the interim.
She recently shared an Instagram post praising Carl for standing by her.
“This man has stuck by me in my most critical times and never done me wrong,” she said.
“The past four months have been challenging for him and I thank him for standing by me and giving me the strength I needed and support through yet again real actual traumas caused by people who I knew.”