William McLean Watson (27 October 1874 – May 1962) became Labour MP for Dunfermline Burghs, Scotland, in 1922. He lost his seat in the National Government landslide of 1931, but won it back in 1935 and retained it until 1950.
Before his career in politics, he was a miner and an official in the Scottish miners' union. He first contested the seat unsuccessfully in 1918.