Sir Billy Mackie Snedden (31 December 1926 – 27 June 1987) was an Australian politician. He was the leader of the Liberal Party from 1972 to 1975, which made him Leader of the Opposition during that tenure. He was also a cabinet minister from 1964 to 1972, and Speaker of the House of Representatives from 1976 to 1983.
Snedden was born in West Perth, Western Australia. He studied at Highgate State School, Perth Boys' School and at Perth Technical College. Snedden was in the Royal Australian Air Force during World War II. In 1950, he married Joy Forsyth. They had four children together.