Executive functions (EFs) relate to a range of important outcomes across the lifespan, yet relatively little is known about the earliest emergence of these skills in infancy and toddlerhood. This chapter provides an overview of the measurement, development, and neural correlates of Early EFs. First, we review current empirical and theoretical frameworks for understanding Early EFs. Then we review key studies to examine how Early EFs have been measured, and what these findings are beginning to reveal about the developmental trajectories of EFs. We then review the neural correlates of Early EFs, before offering some recommendations for how to continue to expand knowledge in this field, with an emphasis on task development.