The MEP is the fifth name to officially enter the race
Sinn Féin has confirmed that MEP Liadh Ní Riada will stand as its candidate for the presidency.
The party's Ard Chomhairle announced the decision after meeting in Dublin to make its final selection.
Earlier in the week, Deputy Ní Riada said she was humbled to be considered:
“Of course, it is a huge honour and very humbling and privileged to be even held in such high regard by people to be put forward as a possible candidate,” she said.
Speaking from the European Parliament in Strasbourg, she said it would be a huge honour to be nominated.
“I have to wait for the process to be completed and see, in respect to all candidates that are putting themselves forward, we have to see what the outcome is,” she said.
There are already four names officially in the race after President Michael D Higgins confirmed he would stand for re-election and three others received the required number of nominations from local authorities.
Businessman Gavin Duffy secured his fourth nomination on Friday – joining fellow Dragon’s Den panellist Sean Gallagher and Senator Joan Freeman on the ballot.
However, according to the latest opinion poll released today, it looks like being an uphill battle for the four challengers.
The poll in the Sunday Business Post puts President Higgins in line for a landslide victory.
The survey has President Higgins way out in front with 67% support, with businessman Sean Gallagher in second on 15%.
The then-unnamed Sinn Féin candidate came in with 7% support, while Gavin Duffy had 6%.
Senator Joan Freeman has 3% support, according to the poll.