Greg held various cabinet, ministerial and parliamentary roles within the Australian Government from 2007 to 2013, including as Minister for Industry and Innovation, Minister for Climate Change and Energy Efficiency and Minister for Defence Personnel, Science and Materiel. Greg was formerly Secretary of Australian Council of Trade Unions and a director of AustralianSuper and briefly sat on the Bank’s Board in 2007 before entering politics.

Greg is Deputy Chair of Industry Super Australia Pty Ltd and a Deputy Chair of IFM Investors (funds management) and Director of Greg Combet Pty Ltd, and also holds a number of consultancy roles and provides advisory services to a range of organisations. He is Patron of Black Lung Victims Group.