The 42-year-old – who returned to television screens for another series of I’m A Celebrity in November after a stint in rehab for painkiller addiction and alcohol problems – described the decision as “very sad”.
His representative said in a statement: “In response to the recent speculation in the media, Ant is very sad to announce that, after 11 years, he is ending his marriage to Lisa McPartlin.
“Ant asks for privacy at this difficult time, for both himself, Lisa and their immediate families. No further statement will be made.”
The couple married in 2006 having known each other for over a decade, but according to The Sun he made the decision to file for divorce “to do the right thing for his health”.
McPartlin entered rehab last summer and a source told the newspaper that his marriage had “effectively been struggling for eight months”.
“They’ve met up and spoken about it a number of times and this is the decision he has made,” the source added.
“They are getting divorced. He is obviously really upset about it.”
McPartlin has spoken publicly about his time in rehab, with his problems having reportedly been triggered by failed knee surgery.
“I’ve spoken out because I think it’s important that people ask for help if they’re going through a rough time and get the proper treatment to help their recovery,” he said last year.
“I feel like I have let a lot of people down and for that I am truly sorry.
“I want to thank my wife, family and closest friends for helping me through this really difficult time.”
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He is still expected to appear alongside long-time on-screen partner Declan Donnelly for their popular Saturday Night Takeaway show when it returns next month.
The popular duo – also known for presenting Britain’s Got Talent – received OBEs from the Queen in January 2017.