John Douglas Williams OAM (born 18 August 1948) is a former Australian politician, who was the Nationals member for Murray-Darling from 2007 to 2015.
He studied economics, accounting and financial management externally through the University of New England.
At the election, he defeated incumbent Labor MP Peter Black on a swing of nearly nine percent, turning Murray-Darling into a safe National seat at one stroke.
In July 2014 it was revealed that Williams had verbally attacked then Coalition cabinet minister Robyn Parker with a sexist slur in April 2014, at a meeting in Parliament House during his bid for pre-selection for the New South Wales Legislative Council.
He was endorsed as a National Party candidate for the Legislative Council, although in the unwinnable fourth position on the ticket, and was defeated accordingly at the election.