Drawing upon research on ingroup and outgroup perceptions, 2 studies examine citizen perceptions of media bias. Study 1 examines how citizens think about media bias across multiple sources. Consistent with the phenomenon of outgroup homogeneity, citizens' political leanings influence how much variation they perceive; politically dissimilar media are seen as having a more uniform partisan bias and politically similar media are seen as having more diverse partisan biases. Study 2 examines whether familiarity, one explanation for outgroup homogeneity, accounts for the patterns. Results demonstrate that familiarity does account for the findings; however, how it does so varies between sources seen as conservative and sources seen as liberal. The study discusses implications relating to theories about media perceptions.