The link between immigration and crime has garnered considerable attention from researchers. Although the weight of evidence suggests that immigration is not linked to crime, the public consistently views immigrants, especially undocumented immigrants, as criminal and thus a threat to social order. However, little attention has been paid to why they are perceived this way. By drawing on the minority threat perspective, this article investigates the effects of objective and perceptual measures of community context on perceived criminal threat from undocumented immigrants. Analyses of data collected from four Southwest states and the U.S. Census show that the perceived size of the undocumented immigrant population, more so than the actual size of the immigrant population and economic conditions, is positively associated with perceptions of undocumented immigrants as a criminal threat. Additional analyses show that objective measures of community context do not affect native respondents’ perceptions of the size of the undocumented immigrant population. The study's findings and their implications for theory, research, and policy are discussed.