Sir Magnus Cameron Cormack KBE (12 February 1906 – 26 November 1994) was a Scottish-born Australian politician.
Born in Caithness-shire, he migrated to Australia as a child, and was educated at St Peter's College in Adelaide. He became a farmer and grazier in the western district of Victoria before serving in the military during World War II, 1940-1945. He served on Kowree Shire Council and was President of the Victorian Liberal Party 1948-1949.
In 1951, he was elected to the Australian Senate as a Liberal Senator for Victoria. He was defeated in the 1953 Senate election, but was re-elected in 1961. On 17 August 1971, he was appointed President of the Senate, succeeding the long-serving Alister McMullin. He held this position until 8 July 1974, when he was succeeded by Labor Senator Justin O'Byrne. He remained a Senator until his retirement, which took effect in 1978.
Cormack was appointed a Knight Commander of the Order of the British Empire (KBE) "in recognition of service to political and public service" in 1970. He died in 1994.