The Boyzone star has three children with his partner Yvonne, Jack, 11, Marie, nine, and four-year-old Ali. They have been married for 12 years and insist the separation is "amicable". They have not revealed why they have decided to part ways.
"With great sadness, Ronan and Yvonne Keating today announce their separation," a statement read. "The separation is amicable and they will continue to work together in order to provide the best for their children. The family ask for privacy at this difficult time."
Ronan`s spokesman has said no further comment will be made.
The 33-year-old singer is still mourning the death of his Boyzone bandmate Stephen Gately, who died suddenly last October.
He is currently promoting the group`s new album Brother, and recently admitted he found it hard to understand why Yvonne was with him.
"I can`t believe Yvonne has stuck with me for so long," he said. "I still get incredibly jealous. The green-eyed monster rears its ugly head and brings out all my insecurities. I don`t like it if Yvonne is out without me. I just can`t help it."