Whereas a majority of previous work has focused on the cognitive factors that influence beliefs, current theory and research suggest that affect also plays an important role. In this article, we comprehensively describe the bidirectional relations between affect and belief. On the basis of our review of existing theory and research, we develop the following three empirically derived premises. First, the need to make sense of experience and the need to regulate affect drive a reciprocal feedback loop through which affect and belief influence each other. Second, changes in affect arousal, valence, and type influence belief content and conviction. Third, changes in belief content and conviction influence affect arousal, valence, and type. We discuss empirical research supporting each premise, needed empirical tests, and avenues for future research.