["Social Science Quarterly, Volume 107, Issue 4, July 2026. ", "\nABSTRACT\n\nObjective\nWe examine the factors affecting attitudes and policy responses to internal migration in Canada, a decentralized federal state. Opposition to internal migration is widespread but far less studied than attitudes toward international migration. Why are some individuals opposed to the relocation of fellow citizens within their own country?\n\n\nMethods\nUsing an original survey of 4052 respondents in Canada, we develop an index of internal‐migration nativism (α = 0.78) and analyze its correlates.\n\n\nResults\nWe find that opposition to internal migration exists in Canada, albeit at lower levels than opposition toward international migrants. Opposition is strongest among individuals with pronounced regional identities and attachments to subnational units, and, unexpectedly, among those who report lower levels of economic anxiety. We then explore factors associated with individual and subnational variations in nativist attitudes.\n\n\nContributions\nThis study provides the first systematic descriptive portrait of attitudes toward internal migrants in Canada, revealing substantial opposition to internal migration within the Canadian federation. By introducing a within‐country measure of nativist attitudes in a decentralized federal context, this study opens new avenues for research on opposition to human mobility across regions and territorial scales.\n\n"]