Brian David Mason (born October 12, 1953) is a Canadian politician who was leader of the Alberta New Democratic Party from 2004 to 2014 and served the Minister of Transportation in Rachel Notley's NDP government. He also served as the Government House Leader. Mason was first elected as a Member of the Legislative Assembly of Alberta for the now-defunct riding of Edmonton Highlands in a 2000 byelection. He was subsequently re-elected, and was elected in Edmonton-Highlands-Norwood after the riding was created in 2004. Mason was currently the longest serving NDP MLA in Alberta history, with a political career spanning over than twenty years.