"Emotional labor" represents a long-standing area of research that since its initial development by Hochschild (1983) has been increasingly explored to understand why and how teachers manage and express their emotions in class. However, previous studies investigating teachers' emotional labor have utilized varying conceptual frameworks and have often shown inconsistent effects, particularly concerning deep acting (i.e., the internalization of desired emotions such that expressed emotions are more consistent with experienced emotions). The current systematic review aimed to outline and summarize existing research findings on teachers' emotional labor and is supplemented by a meta-analytic investigation on the connection between teachers' emotional labor and psychological well-being. Practical implications, limitations, and directions for future research are discussed.