Research exploring motivation has yielded a robust body of evidence to guide efforts to improve teaching and learning in physical education (PE). We begin by defining motivation and achievement within the context of PE. Given the extensive and diverse motivational perspectives, we purposely selected three widely studied theories in PE, achievement goal theory, self-determination theory, and interest theory, as the focus of our review. These theories have guided many investigations and the development of pedagogical practice over the past 3 decades. We elaborate on these theories and then synthesize recently published intervention studies to provide an interpretive analysis of the literature. This analysis has enabled us to identify gaps that need to be addressed in future research and efforts to improve practice. We conclude with the proposition calling for innovative, theory-driven, evidence-based research and practice to foster adaptive student motivation for optimal educational, behavioral, and health outcomes in K–12 PE.