Mairia Cahill has won the Seanad by-election, winning 122 out of 188 valid votes.
She was nominated by the Labour Party to fill the seat vacated by Jimmy Harte.
Four candidates contested this by-election with only TDs and Senators having a vote. The candidates were Mairia Cahill, Independent and former Fianna Fáil campaigner Jerry Beades, Sinn Féin-nominated Councillor Sinead Burke, and Fianna Fáil-nominated Keith Swanick.
However, Mairia Cahill's election was certain as she had the votes of Labour and Fine Gael TDs and Senators.
Keith Swanick of Fianna Fáil was second on 38 votes, Sinéad Burke of Sinn Féin got 18 votes and Independent Jerry Beades received 10.
Speculation is rife on whether Mairia Cahill will run for Labour in the general election - and if so, in what constituency.
In all 225 TDs and Senators had the right to vote. Seventeen did not vote, so a total of 208 votes were cast.
Of those 208, nine did not fill in the identity forms properly or did not return that section, and so their vote did not count.
Of the 199 votes counted, a further 11 were spoiled - five of them contained something other than the preferences, and six did not have the figure 1.
That left 188 votes or a quota of 95. Mairia Cahill won 122 votes on the first count and was deemed elected.
She ran into controversy over her role in the group Republican Network for Unity - where she served as its national secretary for a few hours in 2010. She says she was associated with the group for no longer than six months.
Breaking her silence on the matter in an interview on RTE radio last night after polls closed, Mairia Cahill apologised for joining the dissident group saying it was at a vulnerable point in her life, and said she no longer considered herself to be a Republican.