Ian Douglas Macdonald (born 29 November 1945) is a former Australian politician who served as a Senator for Queensland from 1990 to 2019, representing the Liberal Party.
He was Minister for Regional Services, Territories and Local Government (1998–2001) and Minister for Fisheries, Forestry and Conservation (2001–2006) in the Howard Government.
He was defeated at the 2019 federal election, having been the longest-serving incumbent member of parliament for the final years of his career.