Social and emotional learning (SEL) is an important driver of student well-being, academic achievement, and future success. Despite decades of work on motivation theory and frameworks to promote student motivation and achievement outcomes, connections between motivation and recent frameworks and measures of SEL could be stronger. The purpose of our chapter is to help address this shortcoming. First, we begin by reviewing which theories of motivation currently appear in major SEL frameworks. Second, we introduce how a more comprehensive theory of motivation (based on an expectancy-value-cost framework) could be incorporated into SEL frameworks to advance their overall impact. Third, using examples from our ongoing research in STEM classrooms, we show how a broader knowledge of motivation can inform practitioners on how to promote key SEL competencies and subsequent achievement and engagement for students, especially to address inequities for historically marginalized and minoritized students. Finally, we close with recommendations for future directions for research and practice. [For the complete volume, "Motivating the SEL Field Forward through Equity. Advances in Motivation and Achievement. Volume 21," see ED673001.]