Detention of individuals, generally civilians, in large camps, authorized by goverment and adminstered by the military. Internment camps have also been called "concentration camps", but this term has become synonymous with the Nazi death camps of the Second World War, where millions of civilian Jews were killed. The first sizeable internment camps in what is now Canada were in the Annapolis Valley, Nova Scotia, during the summer of 1755 where thousands of hapless Acadian men, women and children were detained while waiting for ships to deport them. Large-scale internment did not occur in Canada again until the First World War. In 1914, immigrants from Germany, Austria, Bulgaria, Turkey, Croatia, Serbia and the Ukraine were considered "enemy aliens" and had to register within a month. Those who did not were arrested and interned in 24 camps in isolated locations across Canada. 8,579 people, mostly Ukrainians, were interned, and their property and housing seized by the government. One of the largest internment camps was at Spirit Lake in northern Québec where 1,200 people, including 60 women and children, were detained for two years. In 1916, nearly all were released.

Canada used internment camps again during the Second World War. Some opponents to conscription were arrested and detained in camps, including the Montréal mayor, Camilien Houde, who was interned in New Brunswick. Other internees were Italian and German nationals, arrested as enemy aliens. Of the German nationals, the most unfortunate case was that of the German Jews who had fled to Britain, only to be arrested there after war broke out. Mistakenly labelled as "dangerous Nazis", 1,800 were sent to Canada in 1940 for internment, where they were greeted at Québec by troops with fixed bayonets. A number of incidents made Canadian authorities reconsider the status of these men and most were relocated to Fort Lennox, Québec, an historic site before the war. The barbed wire around the fort was mostly removed, and the men of the Veteran’s Guard and the local villagers from nearby Saint-Paul did what they could to help. These innocent and persecuted men were gradually freed but it was only at the end of 1943 that the last 83, by then transferred to Hull, Quebec, were released. Many remained in Canada to start a new life.

Possibly the worst internment incident in Canadian history by its very scope concerned the detention of ‘Japanese’ Canadians. Following Japan’s attack on Pearl Harbour and Hong Kong in December 1941, panic swept the west coast and racism ran rampant, the result being that about 22,000 innocent Canadians of Japanese descent — men, women and children — were arrested and sent to internment camps deep in the interior of British Columbia, their property seized and their livelihoods ruined. Internment conditions were difficult. At Hastings Park camp, for example, there were 10 showers for 1,500 women and toilets consisted of sheet metal troughs with no seats or partitions. Housing consisted of little more than shacks. The internees were released in 1946 and given the choice to resettle in central Canada or be deported to Japan. Canadians of Japanese descent were only allowed to settle in British Columbia again in 1949. This whole episode was an awful and abject act of racism for which the Government of Canada, long after the war, formally apologized. The issue of military internment camps detaining Canadian citizens left uneasy feelings and led to clauses in the 1982 Charter of Rights that, it is hoped, will provide better guidance in future crises.

See also: Prisoner of War