In this article, we conduct a selective review of the literature on emotion regulation in early childhood (e.g., preschool, generally defined as ages 3-5) in regard to school readiness. Emotion regulation (ER), the process of modulating emotional arousal and expression, plays a key role in a child's ability to adapt to novel demands of school environments. This, in turn, has significant implications for both the socioemotional and academic components of a child's readiness to enter kindergarten. We begin our article with a brief review of the ER construct at this developmental stage, then review research on the impact of ER on both components of school readiness during the preschool and early elementary school years. We then discuss strategies for teachers and parents to promote ER strategy use in young children, and end with challenges regarding operationalization at this age and directions for future research. (PsycINFO Database Record (c) 2020 APA, all rights reserved).