The Ipsos MRBI exit poll, commissioned by national broadcaster RTE, The Irish Times, TGA and UCD; showed that ruling center-right Fine Gael of Prime Minister Leo Varadkar on with 22.4 percent, followed by left-wing nationalists Sinn Fein with 22.3 and center-right Fianna Fail on 22.2 percent of the votes.
Official counting will begin at 09:00 local time on Sunday with some results expected from the early afternoon.
These results might prove historic for Ireland as it would be the first time voters chose a left-wing party in such numbers since the nation obtained independence from Britain around a century ago.
Sinn Fein's popularity was helped along by its anti-austerity stances and the backing of young voters seemingly willing to push their country to the left.
The leftist party, which is both active in Ireland and Northern Ireland, has been a major player in the country’s politics, especially for its inflexible position on a united Ireland.
Sinn Fein has been closely tied to the Irish Republican Army (IRA), a designation used by several paramilitary organizations, fighting for all of Ireland to be an independent republic, free from British rule.
The progressive party has thus traditionally struggled to gain wider voters’ support and to convince Irish people that it can lead the nation.
Fine Gael and Fianna Fail have continuously ruled out governing with Sinn Fein and have said they will look to smaller parties to form a coalition or minority government. Both would fall well short of a majority of seats on such a share of the vote.
Ireland's Green Party will likely become a kingmaker as they hold around eight percent of the votes.