Leo Varadkar is officially set to be the next Taoiseach.
87 TDs voted in favour of having him take on the role for the second time in his political career.
62 voted against and one abstained.
The scheduled changeover started with Micheál Martin's resignation this morning, as the government begins the next phase of its tenure.
The historic 'rotating Taoiseach' agreement means that Mr Martin will take on the role of Tánaiste for the remainder of the coalition's term, while Mr Varadkar will lead the government.
"Take comfort that change can happen, even if it takes 100 years."
Mr Varadkar received nominations from party members including Deputies Richard Bruton and Emer Higgins.
Independent TD Michael Lowry reluctantly nominated the Tánaiste too, saying that the government is "not spectacular, but moderately sufficient".
"Take comfort that change can happen, even if it takes 100 years", he said.
Mr Varadkar's term as number two was dominated by issues such as housing, the COVID-19 pandemic and the war between Russia and Ukraine.
Later this afternoon, the Taoiseach-elect will announce his new Cabinet, which will meet properly for the first time at Áras an Uachtaráin tonight.
Few changes are expected in the Cabinet reshuffle, with all eyes on which department Mr Martin will get.
It's expected he'll become the Foreign Affairs Minister, with Simon Coveney to move to Enterprise.
Paschal Donohoe and Michael McGrath are expected to swap the Finance and Public Expenditure briefs.
The Cabinet reshuffle will not bring the change the country needs, Sinn Féin TD Lousie O'Reilly said.
The coalition's policies so far have led to a cost of living crisis, longer waiting lists for healthcare and over 11,000 people homeless, "3,800 of whom are children", she said.
"It's not so much that they didn't deal with [these issues], it's the fact that they got progressively worse on their watch."
"Shifting around the chairs, changing personalities, that is not going to deliver for people."
Main image shows Tánaiste Leo Varadkar. Picture by: PA Images