Several recent studies have documented a pronounced degree of affective polarization between residents of urban and rural areas. Similar to affective polarization between partisans, both urbanites and ruralites tend to exhibit a bias towards their place-based in-group. How these biases arise, however, remains largely unexplored. In this paper, we argue that place-based affective polarization is rooted in misperceptions of what constitutes the political allegiances of typical urbanites and ruralites. We test this proposition by means of three studies. In Study 1, we measure misperceptions of voting behavior along the urban-rural divide, relying on survey items asking respondents to guess the percentage of urban and rural residents voting for a given party. In Study 2, we then investigate the association between misperceptions and place-based affective polarization in an observational setting. Lastly, Study 3 investigates the causal effect of misperceptions on place-based affective polarization in an experiment.