Ray Gietzelt AO (29 September 1922 – 12 October 2012) was a major figure in the Australian union movement in the latter part of the 20th century. He led the Federated Miscellaneous Workers' Union of Australia (FMWU; later known as United Voice) from 1955 to 1984. Ray Gietzelt exerted major influence in the careers of Bob Hawke, Neville Wran and Lionel Murphy, and he was made a Life Member of the Australian Labor Party. The former Australian senator and Sutherland Shire mayor Arthur Gietzelt was his elder brother.