Stephen Roy Williams (born 11 October 1966) is a British Liberal Democrat politician who was first elected as the Member of Parliament (MP) for Bristol West in the 2005 general election, and re-elected with an increased majority in May 2010.
In October 2013 he joined the Government as a Parliamentary Under Secretary of State in the Department of Communities and Local Government.
In May 2015 Williams lost his Bristol West seat to the Labour Party's Thangam Debbonaire, and in May 2017 he came third in the election for the newly created role of Mayor of the West of England.