William Humphrey (born 17 October 1967) is a Democratic Unionist Party politician in Northern Ireland.
Born in the Woodvale area of Belfast, Humphrey studied at the Boys' Model School. A member of the Woodvale Residents' Association, he joined the Democratic Unionist Party, becoming its chairman in North Belfast, and a member of the party's executive.
He was elected to Belfast City Council in the Court district at the 2005 Northern Ireland local elections, then served as High Sheriff of Belfast in 2006.
At the 2007 Northern Ireland Assembly election, Humphrey stood in North Belfast, but was not elected. He moved to contest West Belfast at the UK general election, 2010, but took only 7.6% of the votes cast. In June, he became Deputy Lord Mayor of Belfast,
In September 2010, he was selected to replace Nigel Dodds in the Northern Ireland Assembly, representing North Belfast and was elected at the 2011 Assembly election. Referencing his predecessor, Humphrey said, "Nigel has a proven track record of dedicated hard work on the ground, making a difference in peoples' lives within the Constituency...That will be the record I will strive to emulate."