This article is the Electoral history of John Diefenbaker, the thirteenth Prime Minister of Canada.
A Progressive Conservative, he served one term as prime minister (1957–1963), defeating Louis St. Laurent. He won three general elections (1957, 1958 and 1962), with one majority government and two minority governments. He lost the 1963 election to Lester Pearson, who succeeded him as prime minister. Diefenbaker led the party one last time in the 1965 election, but was again defeated by Pearson.
He stood for election to the House of Commons of Canada fifteen times. He was defeated in his first two attempts (1925, 1926), but he was elected on his third try, in 1940. Thereafter, he was elected an additional twelve times, until he died in office in 1979.
Diefenbaker sought the leadership of the Progressive Conservative Party three times, unsuccessfully in 1942 and 1948, before winning it in 1957. Following the loss in the election in 1965, the party held a leadership convention in 1967 which he lost, ending his leadership of the Progressive Conservative party. Robert Stanfield succeeded him as party leader.
Prior to election to the House of Commons, Diefenbaker was also involved in Saskatchewan provincial politics and municipal politics, but with little success.