The 12-year-old, who came second in Britain's Got Talent, will perform at Hamilton Park Racecourse's Family Night on Saturday, July 9.
Joe, who won the talent show in 2009 has been forced to pull out after making it to the final four of ITV show Popstar to Operastar.
The night's line-up will also include other talent show favourites.
Cute young boyband New Bounce, who also made it to the final's of this year's Britain's Got Talent, are also on the bill. Former X Factor contestants Katie Waissel and Paije Richardson will also perform.
Ashley Moon, commercial manager of Hamilton Park Racecourse, said "We're absolutely thrilled to be adding Ronan to our Family Night billing.
"I'm sure Ronan and New Bounce will enjoy playing to a bumper crowd at our July family fixture and they'll no doubt be pleased to have some friendly faces in Katie and Paije there to support them on the night."
The venue is also hosting gigs by two top boybands this summer.
Westlife will be performing on July 23 and The Wanted on July 22.
Tickets for the Family Night race meeting start from at £13.
For tickets call 01698 283 806 or call www.hamilton-park.co.uk