Judging other people’s personality is a widespread social phenomenon early on in the acquaintance process. The accuracy of these interpersonal impressions colors the way we select, shape, and maintain our social environments. In this chapter, we give an overview of the state of the art in research on the accuracy of personality judgments. First, we describe and discuss existing methodological alternatives (variable- vs. person-centered approaches, choice of accuracy criteria, individual vs. aggregated perceiver approaches). Second, we tackle the question of how well humans can judge the personality of unknown others, summarizing the wealth of existing studies across a large variety of contexts. Third, following a lens model approach, we discuss the cue-expression and cue-perception processes that mediate the amount of judgmental accuracy and summarize initial empirical process insight. Fourth, based on a process understanding we describe domains of moderators that influence how well perceivers can judge others’ personalities (e.g., good trait, good judge, good target, good information). Finally, we highlight a set of issues we deem as important challenges for future research on the accuracy of personality judgments.