Gerry Adams has been selected to run as Sinn Fein's candidate in County Louth in the next Irish general election.
The party leader announced his intention to step down as MP for west Belfast last month and run in the Republic.
On Monday night he officially received the party's nomination at a meeting in Dundalk.
Mr Adams said: "The people of Ireland are looking for a new type of politics.
"The mighty work which has been started in the North can be replicated here. Change is possible and there is a better way for us to manage our affairs.
"My resolve is to seek a mandate, as part of this great Sinn Féin party, to do just that. It is now over to the citizens of Louth and East Meath to decide who should represent them."
If elected he will take Arthur Morgan's seat at the Irish parliament buildings in Dublin.
Mr Morgan announced earlier this year that he planned to step down ahead of the next election, which is due to take place early next year.