Self-regulation refers to a complex of intentional and emergent processes involved in controlling, directing, and planning one's cognitions, emotions, and behavior (Bailey & Jones, 2019;Schunk & Zimmerman, 1997). In investigations beyond the classroom, scientists from a broad range of disciplines have converged on the centrality of self-regulation as a marker of adaptive development (Nigg, 2017). Findings demonstrate, at an emerging level of specificity, how biological and neurological processes interact with psychological and experiential factors to determine how children regulate themselves in a given setting (Hofstee et al., 2022). Biological factors, including an individual's predisposed reactivity and regulation of their reactions to stimuli, underpin these additive and interactive processes (Rueda et al., 2005). Self-regulation also develops through early experiences and social interactions, during which caregivers and teachers structure and shape children's capacities to direct their own actions and regulate impulses (Grolnick & Farkas, 2002;Kopp, 1982;Williford et al., 2017).In this chapter, we examine self-regulation and its role in academic development, focusing on the transition to formal schooling. First, we briefly highlight links between cognitive aspects of self-regulation and academic achievement prior to formal schooling and throughout elementary school; second, we summarize evidence on how three types of self-regulation (cognitive, emotional, and social) interrelate; third, we discuss individual differences and proximal influences on self-regulatory skill growth; fourth, we explore issues of measurement and support in school settings related to children's development of self-regulation. We end with practical implications and suggestions for research.