Gregory Laurence Moriarty (born 4 April 1964) is a senior Australian public servant and diplomat, and the current Secretary of the Department of Defence since 4 September 2017. He was previously the Chief of Staff to Prime Minister Malcolm Turnbull.[2] Moriarty has been Australian Ambassador to Iran from 2005 to 2008, Australian Ambassador to Indonesia from 2010 to 2014, the inaugural Commonwealth Counter-Terrorism Coordinator from 2015 to 2016, and the International and National Security Adviser to the Prime Minister.