Simon Harris will become Ireland's next taoiseach (prime minister).
Aged 37, he is the country's youngest ever leader.
His appointment follows Leo Varadkar's official resignation on Monday.
After a vote in the Irish parliament, he travelled to meet the president to be officially installed.
Thank you for joining our live coverage of today's events in Dublin.
Simon Harris has been nominated as taoiseach by the Irish parliament, to be officially installed in the role this afternoon by the Irish president.
Image source, Maxwell Photography/PA WireSimon Harris was joined by his daughter Saoirse before Tuesday's vote
Image source, PA MediaSimon Harris is travelling to Áras an Uachtaráin, the president's residence, by police escort, to officially become Ireland's youngest leader.
So what has happened today?
Enda McClafferty
BBC News NI political editor
It has all gone according to plan here.
As expected, Simon Harris has been elected taoiseach, the third in the space of four years.
In the end, he had a majority of some 19 votes to spare, so comfortable I think is the right word on the front.
Simon Harris then got to his feet to make his first speech as leader, he talked about the many challenges of course he's going to face now that he is in office.
He talked as well about the challenges north of the border and how he plans to take that next step towards ensuring stability there.
Image source, ReutersSimon Harris says he will work to guard the Good Friday Agreement.
The 1998 peace deal helped bring an end to the Troubles.
Some parties in Northern Ireland are reacting to the nomination of Simon Harris as taoiseach.
Naomi Long of the Alliance Party says she was confident Harris would "continue to nurture this positive partnership between the north and the south".
Colum Eastwood, leader of the Social Democratic and Labour Party, says he looked forward to working with him to strengthen cross-border co-operation "which has suffered as a result of the suspension of devolution in the north".
Simon Harris says he will be a taoiseach for everyone in Ireland.
He continues Ireland’s story was about belief in each other and hope for future.
People should not make the mistake of giving in to pessimism, he adds, but should work together to overcome the challenges it faces.
Simon Harris says he was honoured to meet with Northern Ireland's leaders on Monday.
He says as taoiseach he would be a protector and guarantor of the Good Friday Agreement.
“We have so much more to achieve for all communities on this island and I look forward to working very much with the Northern Ireland Executive,” he says.
He adds Ireland should never take peace or freedom for granted.
Simon Harris says he accepts the new role "in a spirt of humility, ready for the challenge and full of energy and to determination about what can be achieved".
He says he wants to bring "new ideas, energy and a new empathy to public life".
He adds that time is short and there is lots to do.
Harris pledges to "move mountains" to deliver more new homes to the country.
Simon Harris pays tribute to Leo Varadkar and senior Fine Gael politician Simon Coveney who is also leaving the cabinet.
Harris says it is a special day for him and thanks his parents, but adds his biggest thank you goes to his wife Caoimhe and his children.
Image source, OireachtasMaking his first speech after TDs back his nomination, Harris says he will commit "to do everything that I can to honour the trust that you have placed in me today".
He says he intends to lead the government in a spirit of unity, collaboration and mutual respect".
Simon Harris waves to his family in the public gallery as his nomination is backed by 88 votes to 69.
Image source, Oireachtas
Image source, OireachtasTDs have voted to back Simon Harris to become Ireland's next taoiseach.
He will be officially installed after a meeting with the President of Ireland, Michael D Higgins, this afternoon.
Image source, Maxwell Photography/PA WireA roll call vote is being held.
The name of each TD is being called out individually and the deputies are indicating if they are voting in favour of or against Simon Harris becoming taoiseach.
People Before Profit members have held a protest outside the Irish parliament during Tuesday's debate.
Image source, PATDs are currently voting on the proposed nomination of Simon Harris as taoiseach.
You can watch along live by clicking play at the top of this page.
Image source, OireachtasDanny Healy-Rae (right) proposes his brother Michael for taoiseach
Independent Danny Healy-Rae says democracy should not be taken for granted and that he's never seen people so disillusioned and angry.
Fellow independent TD Mattie McGrath says the coalition lack a plan or any empathy for the people of Ireland and Harris offers no prospect of change.
He seconds the proposal of Danny Healy-Rae that his brother, Michael Healy-Rae, should be the next taoiseach, saying he has been active in politics since he was 10 years of age.
Aontú leader Peadar Tóibín accuses Simon Harris of being very good at spin.
He accuses him of being the "Varadkar continuity candidate".
"We are seeing the elevation of a caretaker taoiseach," he adds.
Independent TD Michael Lowry says he could "join in the populist soundbite chorus of negativity" and "contend that everything in the country is a disaster" but that was not his style.
He says there are many issues needing urgent attention, but he does not see how they would be dealt with if they are put in "cold storage" for 10 months while politicians fight a general election.
He adds he will support Harris for taoiseach to help his constituents.
Richard Boyd Barrett of People Before Profit–Solidarity says is it remarkable that the former taoiseach, Leo Varadkar, had "attempted to absolve himself from his government’s failures" by referring to the international origins of the problems.
“That is really quite extraordinary,” he outlines.
Image source, OireachtasHis colleague Mick Barry says Harris has chosen the song "Ain’t Seen Nothing Yet" as his new team song.
He says a better song from the decade might be The Who’s "Won’t Get Fooled Again" which he says might better sum up the mood of the electorate.
In response, the speaker quips the TD might bring a turntable with him next time he appears in the Dáil.
Social Democrats leader Holly Cairns says on a personal note she wishes Simon Harris well.
"However, we are facing serious challenges as a country and in order to address them we need new ideas – for that we need a new government," she says.
"So today the Social Democrats will not be supporting his nomination."
Image source, Maxwell Photography/PA WireShe tells TDs the biggest challenge facing Ireland is a "housing disaster".
"We need a government that will treat is as the national emergency that it is," she says.
Simon Harris has made a pledge of building 250,000 homes between 2025 and 2030.