John Robert Rau SC (born 20 March 1959) is an Australian barrister and politician.

He worked as an adviser to Hawke government ministers Mick Young, Michael Tate and Neal Blewett from 1985 to 1988.

Before his service as a political adviser, Rau worked as a solicitor at Duncan Groom, Carabellas & Hannon.

Prior to the 2002 state election, Rau contested Labor preselection for the safe seat of Enfield.

The seat had previously been Ross Smith, held by Ralph Clarke, who had recently been deposed as the party's deputy leader.

[11] In addition to Deputy Premier and Attorney-General, in the Cabinet of South Australia Rau held the ministerial portfolios with responsibility for justice reform, planning, industrial relations, child protection reform, the public sector, consumer and business services, and with responsibility for the City of Adelaide.