John Robert Rau SC (born 20 March 1959) is an Australian barrister and politician.
He was the 12th Deputy Premier of South Australia from 2011 to 2018 and 48th Attorney-General of South Australia from 2010 to 2018 for the South Australian Branch of the Australian Labor Party in the Weatherill cabinet.
Rau was the Labor member of the House of Assembly seat of Enfield from the 2002 election until announcing his intention to retire from Parliament on 10 December 2018, and submitting his resignation on 17 December 2018.