Why do many people come to believe that they and others have a true self? We hypothesized that this belief emerges because people routinely rely on essentialist reasoning to understand personal identity and the self. Across eight studies, we found that (a) the features that participants attributed to the true self resembled the features typically attributed to essences (e.g., immutability, informativeness, inherence; Studies 1-4); (b) endorsement of belief in true selves correlated with endorsement of other essentialist beliefs (Study 5); and (c) experimental manipulations of essentialist beliefs in domains other than the self spilled over and affected participants' endorsement of belief in true selves (Studies 6-8). These findings advance theory on the origins and functions of beliefs about the true self, suggesting that these beliefs are, in part, a specific downstream consequence of the broader tendency to explain phenomena in the world in terms of underlying essences. (PsycINFO Database Record (c) 2019 APA, all rights reserved).