They have named her Ali and she weighed in at 8lb 3oz.
A spokeswoman said: "Ronan and Yvonne are thrilled and little Ali is doing fine."
Ali is a sister for Jack, six, and Marie, four.
Keating was at his wife's bedside in a Dublin hospital when she gave birth.
The former Boyzone star was playing in the All Star Cup celebrity golf tournament in Wales 10 days ago when he heard Yvonne had gone into labour, but it turned out to be a false alarm.
And the 28-year-old singer may be planning more children.
He said recently: "We said we would stop at two but that moved to three. So who can say if we will stop at three!"
Tweet

Comments
Login or Register to comment
congrats Ronan
Congratulations Ronan and Yvonne. Your mum would be proud of you Ronan. God Bless.
When are you hitting the concert scene again - we miss you . MEN areana two years on the trot - fabulous!
well done ronan for becoming a father fot the 3rd time
hope that mum and baby are do well god bless