Rex Barnes (born June 4, 1959) is a Canadian politician.
Born in Grand Falls-Windsor, Newfoundland and Labrador, Barnes was a member of the Progressive Conservative caucus in the Canadian House of Commons, representing the riding of Gander—Grand Falls. Elected in a by-election in 2002, he lost his seat in the 2004 election to Liberal candidate Scott Simms, running as the member for Bonavista—Exploits.
Barnes has been a paramedic, and a volunteer worker. Barnes was the Progressive Conservative critic for Public Works and Government Services, and Transport. He served as a city councillor in Grand Falls-Windsor for 9 years.
Barnes served as mayor of Grand Falls-Windsor from September 2005 to September 2009.
In February 2011, he announced plans to challenge incumbent MHA Ray Hunter for the Progressive Conservative party nomination in Grand Falls-Windsor-Green Bay South for the 2011 provincial election. Barnes lost the nomination receiving 327 votes to Hunter's 533.
Barnes ran as an independent candidate in Grand Falls-Windsor-Buchans in the 2015 provincial election. He finished in third place with 19.6% of the vote.