Scholars have increasingly employed social identity theory to explain how and why political polarization occurs. This study aims to build off of this work by proposing that perception of intergroup conflict serves as a mechanism that mediates the effect of news media coverage on political polarization. Specifically, I argue that the news media’s emphasis on political animosity can cultivate partisans’ perception that the parties are in conflict, which provides a context that makes partisan identity salient and, ultimately, leads to higher levels of affective and ideological polarization. This hypothesis is tested with an experiment using an American national sample of Democrats and Republicans (N = 300). Participants read a news story in which the public believes the parties are in a state of either high or low conflict (or they did not receive a news story). Using mediation analysis, the results of the study provide evidence that news media coverage of political conflict leads to increased perception of intergroup conflict, which then leads to higher levels of (a) partisan identification, (b) affective polarization, and (c) ideological polarization.