Over the last 30 years, a large body of scholarship has shown that high-quality practices in social and emotional learning can make a substantial difference in children’s educational experiences, and may serve as a powerful lever for transforming children’s learning and positive behavior at scale. Specifically, research indicates that preparing children to be caring, ethical, contributing adults requires supporting them to develop social, emotional, and character skills that include focusing and deploying attention; understanding and managing emotions; empathizing with and respecting others; navigating social conflicts effectively; and standing up for principles of justice and fairness. Throughout history, schools and community centers have served as an important context for building this combination of skills and habits via programs and practices focused on an inter-related set of SEL skills. In this landscape, SEL Kernels are a low-cost and flexible approach that integrates SEL into the daily routines, instructional practices, and activities of schooling. Grounded in a content analysis of 50+ evidence-based SEL programs, SEL Kernels are an alternative to traditional more comprehensive programs, which can be expensive and difficult to implement. Kernels are easy to adapt and localize to fit different educational contexts around the world.