Mark Holland PC MP (born October 16, 1974) is a Canadian politician and current Chief Government Whip. In the 2004 federal election he was elected to the House of Commons of Canada as a candidate of the Liberal Party in the Ontario riding of Ajax-Pickering. Holland was subsequently re-elected in the 2006, 2008, and the 2015 federal elections. He was defeated in 2011 where he became the director of health promotion and public affairs with the Heart and Stroke Foundation of Canada and was subsequently promoted to the roles of executive director for the Ontario Mission and national director of children and youth, before returning to federal politics in 2015. In August 2018, he was promoted to the position of Chief Government Whip.