Robert Menzies, Australian lawyer and politician, 12th Prime Minister of Australia (died 1978)

Sir Robert Gordon Menzies was an Australian politician and lawyer who served as the 12th prime minister of Australia from 1939 to 1941 and from 1949 to 1966. He held office as the leader of the United Australia Party (UAP) in his first term, and subsequently as the inaugural leader of the Liberal Party of Australia in his second. He was the member of parliament (MP) for the Victorian division of Kooyong from 1934 to 1966. He is the longest-serving prime minister in Australian history.

The prime minister of Australia is the head of government of the Commonwealth of Australia. The prime minister is the chair of the Cabinet of Australia and thus the head of the federal executive government. Under the principles of responsible government, the prime minister is both responsible to and a member of the Commonwealth Parliament. The current prime minister is Anthony Albanese of the Australian Labor Party, who assumed the office on 23 May 2022.