The three-time major champion claimed the honours at Adare back in 2007 and has now confirmed his participation for this year's event at Portstewart.
Fellow home favourite Shane Lowry has also been confirmed for the event while Rory McIlroy will also be present, with his foundation hosting the tournament.
Before all that Harrington is due to undergo surgery on a neck injury that could keep him out until June.
It means the Irish Open will be one of his first tournaments back and the 45-year-old says he is already looking forward to teeing it up on the links layout in County Londonderry.
"The Dubai Duty Free Irish Open is always one of the first events I put on my schedule every year and I am really looking forward to playing another classic links golf course in Portstewart in July," he told the European Tour's official website.
"Winning the Irish Open will always be up there with the Major Championship victories as one of the biggest moments of my career and with the event now part of the Rolex Series, it should be a great tournament."