Troed-y-rhiw (Welsh pronunciation: [ˌtrɔi̯d ə ˈr̥ɪu̯], translation: foot of the slope) is a large community village in the county borough of Merthyr Tydfil, Wales. Its population at the 2011 census was 5,296. It features the Troed-y-rhiw railway station.

The community shares a border with the electoral ward of Plymouth, which elects three county councillors to Merthyr Tydfil County Borough Council. At the May 2017 elections the ward re-elected three Labour Party councillors.

In 2007 the Troedyrhiw Environment Forum joined the Community Archives Wales programme. The Environment Forum is a part of the Troedyrhiw Community Partnership which has approximately 30 registered members who attend all kinds of different forums including a Residents Association, Scouts Group and Old Age Persons Group. The Environment Forum has engaged all parts of the community in a range of community projects, including the Trevithick Heritage Trail.

• Welsh international footballer Charlie Jones, who played for Nottingham Forest and Arsenal in the 1920s and 1930s, was born in Troed-y-rhiw in 1899.
• His Welsh international colleague Willie Davies, who played for several clubs, including Cardiff City and Tottenham Hotspur in the 1920s and 1930s, was born in Troed-y-rhiw in 1900.
• Bobby Weale was another footballer born (in 1903) in Troed-y-rhiw. His career took him to Swindon Town and Southampton before returning to Wales to play for Cardiff City, Newport County and Wrexham.
• Footballer Jim Lewis was born in Troed-y-rhiw in 1909 and played at left back for Watford from 1930 to 1939.
• His younger brother, George Lewis was also born in Troed-y-rhiw (in 1913) and played football as a centre forward, first for Watford and then for Southampton.
• Footballer Gwyn Jones, who played for Rochdale and Stockport County, was born in Troed-y-rhiw in 1912.
• Vivian Woodward was born in Troed-y-rhiw in 1914 and played at inside-forward for Fulham from 1936 to 1947, with later spells at Millwall, Brentford and Aldershot, as well as playing once for Wales.
• Actor Steve Speirs was born in Troed-y-rhiw in 1965.

• Old Merthyr Tydfil: Troedyrhiw - Historical Photographs of Troedyrhiw.
• www.geograph.co.uk : photos of Troed-y-rhiw and surrounding area
• Zulus and Stone Breakers: A Case Study in Glamorgan Ballad-Sheet Printing (1999)
• Watching the White Wheat and That Hole Below the Nose: The English Ballads of a Late-Nineteenth-Century Welsh Jobbing-Printer (2000)
• Golwg ar Rai o Gerddi a Baledi Cymraeg Troed-y-rhiw (2001)

51°42′44″N 3°20′42″W / 51.71222°N 3.34500°W / 51.71222; -3.34500