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.

[2][5] In the 1997 general election Williams stood as the Liberal Democrat candidate for Bristol South, where he came third with 13.4% of the vote.

In this role he served on the committee that scrutinised a health bill that introduced a ban on smoking in public places.

[10][11] On 29 November 2005, Williams introduced a Ten Minute Rule bill to the House of Commons to reduce the voting age to 16.

After the reorganisation of government departments by new prime minister Gordon Brown in July 2007, Campbell reshuffled his team and Williams became the party's spokesperson on schools.

Williams served as chair of the All Party Parliamentary Group on Smoking and Health between July 2010 and October 2013.

[20] In October 2013, Williams was appointed Parliamentary Under Secretary at Department for Communities and Local Government (DCLG).

[22] In 2017, it emerged that Williams had responded to 2014 concerns from the All-Party Parliamentary Fire Safety and Rescue Group about the fire safety of Britain's tower blocks, especially the absence of sprinklers in many of these, by saying, "I have neither seen nor heard anything that would suggest that consideration of these specific potential changes is urgent and I am not willing to disrupt the work of this department by asking that these matters are brought forward."

[23][24] In the 2015 United Kingdom general election, Williams lost his seat to Labour Party candidate Thangam Debbonaire.

Before the election, he said he was concerned about losing support amongst students for abstaining on the vote to increase tuition fees to £9,000 a year.

[28] In the 2019 European Parliament election, he was selected as the third candidate on the Liberal Democrat list for South West England.

[32] In November 2023, it was announced that Williams would be one of three Liberal Democrat candidates for the Westbury-on-Trym & Henleaze Ward in the 2024 local elections.