Prohibition in Canada was a ban on alcoholic beverages that arose in various stages, from local municipal bans in the late 19th century (extending to the present in some cases), to provincial bans in the early 20th century, and national prohibition (a temporary wartime measure) from 1918 to 1920. The relatively large and powerful beer and alcohol manufacturing sector, and the huge working class that purchased their products, failed to convince any of the governments to reverse their stance on prohibition. Most provinces repealed their bans in the 1920s, though alcohol was illegal in Prince Edward Island from 1901 to 1948. By comparison, the Ontario Temperance Act was in effect from 1916 to 1927.

As legislation prohibiting the consumption of alcohol was repealed, it was typically replaced with regulation imposing restrictions on the sale of alcohol to minors, and with excise taxes on alcoholic products.

Canadians drank heavily during the 19th century. The 1851 census of Upper Canada recorded 1,999 taverns or one to 478 people. Drunkenness, fighting, domestic abuse, and household impoverishment were rampant.

Prohibition was mostly spurred on by the organized crusades against social evil launched by the temperance movement. They targeted drinking establishments, which they viewed as the source of societal ills and misery. Initially, the temperance movement in Canada, which began in the 1820s, was largely concerned with the consumption of strong liquor, while beer, wine, and cider were not considered to be a significant problem. However, by the 1840s, "total abstinence" temperance societies were the norm, and all alcoholic beverages, including those with lighter alcohol content, were considered dangerous. Inspired by the Maine Law of 1851, which saw legal prohibition in the U.S. state of Maine, the temperance movement in Canada shifted to the strategy of legal coercion to advance the cause of sobriety.

The main temperance organizations that emerged at the beginning of the prohibition era in Canada were the Dominion Alliance for the Total Suppression of the Liquor Traffic and the Woman's Christian Temperance Union (WCTU) of Canada. Protestant denominations, including Baptists, Methodists, Presbyterians, and Congregationalists, generally supported prohibition and campaigned for it beginning in the late 19th century. Notable advocates included Archibald McKillop, a Scottish-Canadian blind poet and orator from the Eastern Townships who promoted sobriety through public speeches and verse. Prohibition was an important aspect of the Protestant Social Gospel.

The WCTU established itself throughout much of Canada and the United States as one of the largest and most influential contributors to the temperance movement. One way the WCTU attempted to spread the message of temperance was by pressuring provincial governments for temperance instruction in schools. In 1892, under pressure from the WCTU and other temperance organizations, Nova Scotia enacted legislation requiring schools to teach students about the effects of alcohol on the human body. By the end of the 19th century, through the efforts of the WCTU, most provinces had at least some temperance instruction in school. The WCTU also looked outside of the formal school systems to promote temperance ideals to children, and also spread their message to Sunday schools, and youth groups.

The Dominion Alliance was an umbrella organization that "included representatives from most temperance and prohibition societies," including the WCTU. The group lobbied governments at various levels to enact prohibitory laws, and other legislation that advanced the cause of temperance. They submitted a memorial, or a written statement of principles, to the nineteenth session of the Huron Diocese's Anglican Synod in 1876. In it they stated:

The Council of the Alliance has agreed to the following principles as a basis to which they most respectfully but earnestly call your attention: