Duncan John Gay (born 2 May 1950), an Australian politician, was the Vice-President of the Executive Council of New South Wales and the Leader of the Government in the Legislative Council from May 2014 to January 2017; and the Minister for Roads, Maritime and Freight from April 2015 to January 2017. Gay was the Leader of the Nationals in the Legislative Council until January 2017 and was a member of the Council from 1988 to 2017, representing The Nationals.