This study aims to investigate the relationships between citizens’ populist attitudes, perceptions of public opinion, and perceptions of mainstream news media. Relying on social identity theory as an explanatory framework, this article argues that populist citizens assume that public opinion is congruent with their own opinion and that mainstream media reporting is hostile toward their own views. To date, only anecdotal evidence suggests that both assumptions are true. The relationships are investigated in a cross-sectional survey with samples drawn from four Western European countries (N = 3,354). Multigroup regression analysis supports our hypotheses: False consensus and hostile media perceptions can clearly be linked to populist attitudes in all four regions under investigation. Moreover, our findings show a gap between hostile media perceptions and congruent public opinion perceptions, which increases with increasing populist attitudes to the point that the persuasive press inference mechanism is annulled.