Sir John McEwen (March 29 1900 - November 20 1980), Australian politician and 18th Prime Minister of Australia, was born at Chiltern, Victoria, where his father was a pharmacist. He was eductated at state schools and at 16 he became a junior public service clerk. As soon as he turned 18 he enlisted in the Army, but the First World War ended while he was still in training and he was discharged. He took up dairy-farming at Stanhope, near Shepparton.

McEwen was active in farmer organisations and in the Country Party. In 1934 he was elected to the House of Representatives for Echuca, switching to Indi in 1937 and Murray in 1949. Between 1937 and 1941 he was successively Minister for the Interior, for External Affairs and for Commerce and Agriculture. In 1940 when Archie Cameron resigned as Country Party leader he contested the leadership ballot against Sir Earle Page: the ballot was tied and Arthur Fadden was chosen as a compromise.

When the conservatives returned to office after eight years in opposition in 1949, McEwen became Minister for Commerce and Agriculture again, then Minister for Trade and Industry. He pursued what became known as "McEwenism" - a policy of high tariff protection for manufacturing industry, so that industry would not challenge the continuing high tariffs on imported raw materials, which benefitted farmers but pushed up industry's costs. In 1958 Fadden retired and McEwen succeeded him as Country Party leader.

When Robert Menzies retired in 1966, McEwen became the longest-serving figure in the government, and he had a right of veto over government policy. When Harold Holt died in 1967, the Governor-General sent for McEwen and he was sworn in as caretaker Prime Minister while the Liberals elected a new leader.

There was some support even among Liberals for McEwen taking the job permanently, but he contented himself with vetoing the Treasurer (finance minister), William McMahon. McEwen disliked McMahon personally (probably because of the rumours that he was homosexual) and also politically, because he suspected McMahon was a free trader. McMahon withdrew from the leadership ballot and John Gorton was elected.

McEwen retired in early 1971, and his retirement freed the Liberals to move to replace Gorton with McMahon, which they did within two months. McEwen died in 1980, by which time the Fraser government was abandoning McEwenite trade policies.