Stephen Roy Williams (born 11 October 1966) is a British Liberal Democrat politician who served as Member of Parliament (MP) for Bristol West from the 2005 general election until his defeat by Labour Party candidate Thangam Debbonaire in 2015. As an MP, he served in the Cameron–Clegg coalition government as Parliamentary Under-Secretary of State in the Department of Communities and Local Government from 2013 to 2015.