Alan John Williams (14 October 1930 – 21 December 2014) was a British Labour politician who served as Member of Parliament (MP) for Swansea West for over 45 years, from 1964 to 2010.

He was the longest serving MP for a Welsh constituency since David Lloyd George and built a reputation for his detailed scrutiny of the ways in which public money was spent.

[1] The constituency, containing the city centre, the university and the relatively prosperous western suburbs, had historically been a marginal one for Labour, in contrast to the more working-class Swansea East.

Percy Morris, elected in the Labour landslide of 1945, had seen his majority cut to just over a thousand votes in 1955 before the Conservative Hugh Rees unseated him four years later.

[1] His majorities thereafter were more secure but the fact that the Liberal Democrats came close to winning the seat after his retirement in 2010 suggests that he had a substantial personal vote.

When Labour were returned to power at the February 1974 general election, Williams was made Minister of State at the Department of Prices and Consumer Protection, serving until Wilson left office in 1976.