Rhondda West was a parliamentary constituency centred on the Rhondda district of Wales.
It returned one Member of Parliament (MP) to the House of Commons of the Parliament of the United Kingdom, elected by the first past the post system.
The constituency was created for the 1918 general election, and abolished for the February 1974 general election.
Throughout its existence the constituency included the towns of Treorchy and Tonypandy.
1918–1974: The Urban District of Rhondda first, second, third, fourth, and fifth wards, and part of the sixth.