Downer joined the Australian Department of Foreign Affairs in 1976, serving at the Australian Embassy in Belgium, was elected to the Federal Parliament as a Liberal member for Mayo, South Australia in 1984 and held this seat until retirement from Parliament in July 2008. During his time in Parliament he was Australia's Minister for Foreign Affairs from 1996 to 2007.
He has held the position of the United Nations Special Adviser to the Secretary-General on Cyprus.
Downer was appointed Australian High Commissioner to the United Kingdom in March 2014.
- BA Politics and Economics from Newcastle University.
- Resourcehouse - Downer is a director of this Hong Kong-based firm owned by Australian resources magnate and politician Clive Palmer 
- Ian Verrender, Be careful of the company you keep, Sydney Morning Herald, 31 March 2012, accessed 29 September 2014. http://www.smh.com.au/business/be-careful-of-the-company-you-keep-20120330-1w35j.html
- The Hon Alexander Downer profile Australian Government, Department of Foreign Affairs and Trade, undated, accessed 25 September 2015
- Ian Verrender, Be careful of the company you keep, Sydney Morning Herald, 31 March 2012, accessed 25 September 2014
- Companies House. Company filing history for Holdingham International Advisory Board, Company no.03092560, accessed 12 September 2014