David Alfred Thomas, 1st Viscount Rhondda, PC (26 March 1856 – 3 July 1918), was a Welsh industrialist and Liberal politician. He was UK Member of Parliament (MP) for Merthyr Tydfil from 1888 until the January 1910 general election, then MP for Cardiff until the December 1910 general election, when he left politics to concentrate on his business interests. He was made a member of the Privy Council in 1916. He later held office, notably as "Food Controller" in Lloyd George's wartime coalition government.