For more than 150 years, politicians, the federal government, and missionary churches misled Canadians about deaths, abuse, and the genocidal intent in residential schools for Indigenous children. More recently, the identification of suspected unmarked graves at former school sites has triggered a renewed spread of misinformation denying the harmful legacy of residential schools. To what extent does the Canadian public endorse residential school denialism? Can education counter this misinformation? In this study, we develop and test a scale for measuring residential school denialism. We find that nearly one in five non-Indigenous Canadians agree with denialist claims, while an equal share feel they do not know enough to offer an opinion. Denialist beliefs are more common among men, conservatives, those with anti-Indigenous attitudes, and white Canadians who strongly identify with their racial in-group. In an experiment, we also show that educational information reduces non-opinions and increases the likelihood of rejecting denialist arguments.