The Health Minister Simon Harris and his wife Caoimhe have become parents.
The baby girl was born on Friday.
Writing on his official Instagram account earlier, Mr Harris said: "Today I take on my most important job - Dad!
"Caoimhe and I are delighted to welcome our beautiful little daughter into the world. Name to follow!
"So happy. Who knew you could be so bowled over and blown away".
Initially not giving a name, Mr Harris later said the couple settled on 'Saoirse' - the Irish word for 'freedom'.
In a small twist, Mr Harris' daughter shares a birthday with the Taoiseach Leo Varadkar.
Mr Varadkar is marking his 40th birthday.
???????WATCH: On the Taoiseach's birthday, we take a look at how @campaignforleo's candle counting compares to his peers. pic.twitter.com/QMcEMaqkxX
— Newstalk (@NewstalkFM) January 18, 2019