Patrick Costello (39) was one of 12 Green Party councillors elected in 2014 before the party's electoral fortunes were buoyed by a "Green wave" last year that has continued and carried him into the Dáil.
The party spokesman on transport, Costello took the third seat in Dublin South Central in the 2020 general election.
Costello won a seat on Dublin City Council in the 2014 local elections, and not only retained his seat but topped the poll in the Kimmage-Rathmines ward last May in an election that saw the party take 49 council and two MEP seats.
He is the partner of party chair Hazel Chu, who is a councillor in the Pembroke ward of Dublin City Council. The pair met while in University College Dublin, where Costello was studying psychology.
Employed as a social worker, Costello previously worked in homeless and addiction services, and volunteers as a scout leader.
