William John "Bill" Kelty, AC (born 5 February 1948) is an Australian trade unionist and a well-known figure in the Australian labour movement, who served as Secretary of the Australian Council of Trade Unions (ACTU) from 1983 to 2000.
Born in Brunswick, Melbourne, Kelty was educated at La Trobe University where he studied economics. His professional union activity began in 1975 as a research officer for the Federated Storemen and Packers' Union (now part of the National Union of Workers).
He was one of the authors of The Accord between the unions and the Labor government, and was Paul Keating's witness to the Kiribilli Pact concerning leadership of the Australian Labor Party.
He has been a Commissioner of the Australian Football League (AFL) since 1998.
He was made a Companion of the Order of Australia in 2008.