Justice Minister Helen McEntee has given birth to a baby boy.
Ms McEntee has become the first sitting Cabinet Minister in the history of the State to give birth while in office.
He was born in the Rotunda Hospital in Dublin last night, weighing seven pounds and eight ounces, her spokesman has confirmed.
Mother and baby are both doing well, he added.
The baby arrived just one day after Ms McEntee took maternity leave.
However, she will remain a member of government, serving as a Cabinet minister without portfolio until she returns.
Politicians have rushed to congratulate Ms McEntee on her new arrival.
Paying tribute to her in the Dáil, her party leader and Tanaiste Leo Varadkar said "history has been made today".
He said: "I would just like to join with you in offering my sincere and heartfelt congratulations to Helen McEntee, who was delivered of a baby boy last night, and also to her husband Paul Hickey.
"They have made history. This is the first time that a serving member of Government in Ireland has given birth.
"When it comes to equality and diversity it's often said that people need to see it before they know they can be it.
"I hope that young women and girls will see today that in Ireland you can hold high office, take maternity leave and raise a family, and be supported to do so.
"Of course we have more work to do in this area. But it is a positive day and history is being made today by the McEntee and Hickey family."
Taoiseach Micheal Martin tweeted: “Congratulations @HMcEntee and Paul on the birth of your wonderful baby boy. A time of great joy for you all. Enjoy! Wishing you every happiness, always.”
Heather Humphreys, who will temporarily take over Ms McEntee’s justice role, has also wished her well.
She tweeted: “It’s a good job we had the handover a few days early! So delighted for @HMcEntee
“A fantastic role model for young women. Helen might be the first serving Cabinet Minister to have a baby but she certainly won’t be the last!”
It is expected that legislation will follow to allow serving politicians to take full maternity leave, with the arrangements in place for the Minister described as a “sticking plaster”.
Ms McEntee said on Tuesday: “It’s really important that women see other women in roles and positions being able to take maternity leave, being able to return to their jobs and return to the positions that they were working in before.
“Most importantly, what I hope to see in the future is that this won’t just apply to me but that other Ministers, TDs, senators, councillors, will be able to avail of maternity leave.”
She added: “This is very much a sticking plaster, it’s not a long term measure.”
The Citizen’s Assembly on Gender recently recommended that maternity leave be put in place for all elected representatives.
