The Canadian federal election of 1957 was held June 10, 1957, to elect members of the 23rd Parliament of the Canadian House of Commons. An unexpected victory by the Progressive Conservative Party, led by John Diefenbaker, brought an end to 22 years of Liberal government.

The Liberals had won several consecutive elections on programs of successful fiscal management and moderate and conciliatory policies. By the 1950s, many believed that the party was arrogant and too close to business. Controversial debates, such as the 1956 "Pipeline Debate" over the construction of the Trans-Canada Pipeline, had hurt the government and exposed it to charges of arrogance. In addition, Western Canadians felt alienated from a government that they believed was dominated by Ontario and Quebec interests. Louis St. Laurent, nicknamed 'Uncle Louis', was still popular, but many felt he had lost touch with ordinary Canadians.

In 1956, the PC party had elected the fiery and charismatic Diefenbaker as their leader. Many people disliked him and felt that he did not have enough experience to be a strong challenger to the Liberals. Because they believed that there was little hope of defeating the Liberals in the next election, many Tories supported Diefenbaker as a caretaker leader.

The PC campaign was based on Canadian nationalism and the need for a change. The "Tories" also embraced their Red Tory side, pledging to out-spend the Liberals on social programs. The Liberals were attacked as free marketers who would leave the Canadian population without an adequate safety net. One of the most ambitious elements of the Tory program was the "New Frontier Policy" of infrastructure development that would lead to the populating of the north.

The Liberal campaign was far less ambitious, supporting a stay-the-course message with moderate reforms and a continuation of competent administration. The economy was booming and the Liberals felt this was enough to win a re-election. The Liberals also had ammunition to use against Diefenbaker: he was a member of the Orange Order and had a history of making anti-Catholic statements.

However, the Tories' greatest asset soon turned out to be Diefenbaker. His ethnic background attracted a new group of supporters to the traditionally Anglo-Saxon Tory party. He was also able to use his charisma to great success. This was the first Canadian election to be televised, and while only a minority of Canadians owned a television, most got some opportunity to see the candidates they were voting for. Diefenbaker was viewed as honest and dedicated, while the 75 year old St. Laurent was felt to be distant and humourless.

The worst moment for the Liberals, however, would be a rally at Maple Leaf Gardens in Toronto. While St. Laurent spoke on the stage, a 15 year old protester jumped on stage and tore up a poster. When security came to bring the boy off stage, he fell down a set of stairs and hit his head on the concrete floor, knocking him unconscious. While the boy turned out to be fine after being revived, the optics of having an opponent being hurt at the rally stung the Liberals. Diefenbaker would use this example in speeches, echoing the Pipeline Debate and percived Liberal arrogance against opponents.

Social Credit campaigned on a platform of lowering personal income taxes by raising the basic amount of income exempt from tax by 50 percent to compensate for inflation; providing an old age pension of $60 per month for all pensioners, plus $40 a month extra for those in need; a national medicare plan for those provinces than want it; "parity prices" for farmers, and a program to sell surplus agricultural products to developing nations by accepting their own currencies instead of requiring payment in Canadian or US dollars; low-interest, long-term loans to encourage house construction; an income tax deduction for mortgage interest; and an end to the Bank of Canada's "tight money" policy. Social Credit won four additional seats, and increased its share of the popular vote by a small amount.

The campaign was also the first in Canada to use modern political advertising techniques. PC strategists such as Dalton Camp and Allister Grosart ran a more tightly-planned campaign than any in Canadian history. An important strategy was almost completely ignoring the province of Quebec -- the PC strategists felt they had little chance there. They also believed they could win without the province.

In an era before widespread polling, the results of the election came as a surprise to most Canadians, including most politicians. The Liberals won the popular vote, but lost the election as they piled up massive majorities in Quebec. In the West, Ontario, and the Maritimes, the Tories gained enough seats to form a minority government. Noted Liberal ministers like C.D. Howe, the "Minister of Everything", lost their seats.

Many Canadians were overjoyed to see change, and spontaneous celebrations occurred in many parts of the country. The Canadian Broadcasting Corporation anchor covering the election famously lit a cigar in satisfaction with the results.