Sinn Féin's Mr Seán Crowe has topped the poll in Dublin South West, marking a significant increase in support for Sinn Féin across the State.
Mr Crowe, who said the victory as a "massive endorsement for Sinn Féin", was elected when he exceeded the quota after the first count. He received 7,466 first-preference votes.
Speaking after the result was announced, Mr Crowe said he did not expect to be the only Sinn Féin TD returning to the 29th Dáil predicting victories for his party colleagues Mr Martin Ferris in Kerry North, Mr Aengus O'Snodaigh in Dublin South Central, and Mr Caoimhghín O'Caoláin in Cavan-Monaghan.
Sinn Féin president Mr Gerry Adams said the election of Mr Crowe had given Sinn Féin the endorsement they needed for their current strategy in the peace process.
Mr Crowe, is the first Sinn Féin TD elected in Dublin since Countess Markievicz in 1927.
The battle for a Sinn Féin seat in Dublin South West began in earnest in 1997, one day after the battle for a seat in the 28th Dáil was foiled when its candidate, Cllr Crowe, was eliminated with one-third of a quota.
Since then the party has poured its resources into the constituency, particularly since the 1998 Boundary Commission changes, which cut the constituency from a five- to a four-seater.
Over the last year Mr Crowe's chances have waxed and waned in the opinion polls, with some commentators arguing that he had peaked last summer.