Gregory Ivan Combet (; born 28 April 1958) is a former Australian politician and trade unionist.
He was Secretary of the Australian Council of Trade Unions between 1999 and 2007.
He was elected member for the New South Wales Federal seat of Charlton for the Australian Labor Party at the 2007 election and was immediately appointed Parliamentary Secretary for Defence Procurement in the First Rudd Ministry on 3 December 2007.
Combet was the Minister for Climate Change, Industry and Innovation in the Second Gillard Ministry before announcing his resignation from the ministry on 26 June 2013 following Julia Gillard's defeat in a leadership ballot.
He previously served as Parliamentary Secretary for Climate Change, when Penny Wong was the Minister.
He retired from politics at the 2013 election.