Cyfarthfa mainly consists of the settlements of Gellideg and Heolgerrig and Rhyd-y-car area just west of Merthyr Tydfil town.

[4] Subsequent to 1995 Cyfarthfa became an electoral ward to Merthyr Tydfil County Borough Council, electing three councillors.

Councillor Les Elliott resigned only two months later on health grounds,[7] triggering a by-election which took place on 15 November 2012.

The by-election was won by Labour's Margaret Davies, who beat the replacement Merthyr Independents candidate by 21 votes.

[8] Sitting Independent councillor, Paul Brown, died in February 2019, leading to a by-election being held on 11 April 2019.