The things teachers do in class have an important influence on their students’ motivation, engagement, and learning. This study uses an international expert panel to identify the teacher behaviors most likely to influence motivation—specifically, teacher behaviors that increase the more healthy, autonomous motivation that comes from within students. This list of behaviors, agreed upon by the experts, could be used by teachers trying to improve their practice, policymakers trying to scale interventions, and researchers trying to assess which behaviors best predict student outcomes.