|OS grid reference|
|Sovereign state||United Kingdom|
|Post town||Merthyr Tydfil|
|Dialling code||01685 38|
Cyfarthfa mainly consists of the settlements of Gellideg and Heolgerrig and Rhyd-y-car area just west of Merthyr Tydfil town. It is mostly bordered to the east by the A470 trunk road and to the north by the 'Heads of the Valleys' A465. Cyfarthfa Castle is located just to the east in the neighbouring community of Park. Cyfarthfa has strong historical ties to the industrial past of Merthyr Tydfil, the site of Cyfarthfa Ironworks was just to the east, by the River Taff.
Subsequent to 1995 Cyfarthfa became an electoral ward to Merthyr Tydfil County Borough Council, electing three councillors. Since 1995 the ward has largely elected Independent councillors standing under a variety of tickets, with the occasional Labour Party councillor. At the May 2017 elections the vote in Cyfarthfa was delayed until 8 June, because of the death of one of the candidates, Ieuan Harris. The result was seats being won by Geraint Thomas (Independent), Paul Brown (Merthyr Independents) and David Chaplin (Labour). The turnout was the highest in the borough, at 64%.
Following the May 2012 elections Cyfarthfa was represented by two Merthyr Independents. Councillor Les Elliott resigned only two months later on health grounds, 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.
Sitting Independent councillor, Paul Brown, died in February 2019, leading to a by-election being held on 11 April 2019.
- "Election maps". Ordnance Survey. Retrieved 17 April 2019.
- Cyfarthfa Ward 2001 Census: Census Area Statistics: National Statistics. UK government. Retrieved 30 January 2011
- "Community population 2011". Retrieved 9 November 2015.
- "The County of Mid Glamorgan (Electoral Arrangements) Order 1988". legislation.gov.uk. The National Archives. 2 March 1988. Retrieved 17 April 2019.
- Merthyr Tydfil County Borough Council Election Results 1995-2012, The Election Centre. Retrieved 31 October 2018.
- "Independents win control of Merthyr Tydfil council and oust Labour after delayed ward vote". Wales Online. 9 June 2017. Retrieved 2 November 2018.
- "Merthyr councillor Les Elliott resigns, sparking by-election". Daily Post. North Wales. 26 July 2012. Retrieved 3 November 2018.
- "Election results for Cyfarthfa - Cyfarthfa Electoral Division By Election - Thursday, 15th November, 2012". Merthyr Tydfil County Borough Council. Retrieved 3 November 2018.
- "Date of Merthyr Tydfil Council by-election is announced". Wales Online. 10 March 2019. Retrieved 14 April 2019.
- Old Merthyr Tydfil: Cyfarthfa - Historical Photographs of Cyfarthfa