Recognising population growth, South Dublin County Council gained 14 seats since 2009. Sinn Féin emerged as the largest party after the local elections with 9 seats and 6 gains in total. The party won 2 seats in each of Clondalkin and the 2 Tallaght LEAs. Fine Gael retained second place but lost 1 seat overall to emerge with 7 seats. While the party won 2 seats in each of Clondalkin, Lucan and Rathfarnam she won no seat in either Tallaght LEA. Fianna Fáil gained 1 seat to win 5 seats overall, in the Lucan LEA, the first time they won a seat there since 2004, but were left without representation in Tallaght South. Labour were the big losers, losing 5 seats to emerge with 4 overall and were left without representation in Lucan and Rathfarnam. Both People Before Profit and the Anti-Austerity Alliance secured 3 seats each. The Green Party also gained 1 seat in Rathfarnam. Independents were also among the biggest winners on the Council with 8 seats and 7 gains in total.
^Clondalkin Sinn Féin Cllr Eoin O Broin was elected as a TD for Dublin Mid-West at the Irish general election, 2016. Mark Ward was co-opted to fill the vacancy on 14 March 2016.[1]
^Clondalkin Sinn Féin Cllr Jonathan Graham resigned from Sinn Féin and became an Independent citing that his time in the party had been a mostly negative experience.[2] He joined Fianna Fáil on 22 March 2019.[3]
^Clondalkin People Before Profir Alliance Cllr Gino Kenny was elected as a TD for Dublin Mid-West at the Irish general election, 2014. Madeleine Johansson was co-opted to fill the vacancy on 3 April 2016.[4]
^Rathfarnam Fianna Fáil Cllr John Lahart was elected as a TD for Dublin South-West at the Irish general election, 2016. Emma Murphy was co-opted to fill the vacancy on 14 March 2016.[5]
^Rathfarnam Fine Gael Cllr Anne-Marie Dermody resigned in September 2017 citing difficulties balancing work and life pressures.[6] Conor McMahon was co-opted to fill the vacancy on 14 November 2017.[7]
^Rathfarnam Independent Cllr Deirdre O'Donovan joined Fianna Fáil and ceased to be an Independent on 21 February 2019.[8]
^Tallaght Central Sinn Féin Cllr Máire Devine was elected as a Senator on 25 April 2016. Cora McCann was co-opted to fill the vacancy.
^Tallaght Central Labour Cllr Mick Duff resigned from the Labour Party and became an Independent saying Labour was struggling for relevance on 5 October 2018.[9]
^Tallaght South Labour Cllr Martina Genockey resigned from the Labour party and became an Independent saying Labour was not best placed to eradicate poverty and disadvantage in its present form on 28 September 2018. She will not contest the next local elections.[10]
^Tallaght South PBPA Cllr Nicky Coules resigned due to his COPD illness in September 2017.[11] Emma Hendrick was co-opted to fill the vacancy on 25 September 2017.[12]
^Tallaght South Independent Cllr Dermot Richardson joined Sinn Féin in April 2016.[13]
^Templeogue-Terenure Independent Cllr Dermot Looney joined the Social Democrats on 8 June 2017.[14]
^On 13 March 2015 Templeogue-Terenure Independent Cllr Ronan McMahon became a founder member of the Renua party.[15]
^Templeogue-Terenure Sinn Féin Cllr Fintan Warfield was elected as a Senator on 25 April 2016. Enda Fanning was co-opted to fill the vacancy. He resigned his seat on 10 October 2017.[16] On 31 October 2017 Robert Russell was co-opted to fill the vacancy.[17]
^Templeogue-Terenure Fine Gael Cllr Colm Brophy was elected as a TD for Dublin South-West at the Irish general election, 2016. Brian Lawlor was co-opted to fill the vacancy on 14 March 2016.[18]
