The present contribution provides a conceptualization of teacher emotions rooted in appraisal theory and draws on several complementary theoretical perspectives to create a conceptual framework for understanding the teacher emotion-student outcome link based on three psychological mechanisms: (1) "direct transmission effects" between teacher and student emotions, (2) "mediated effects" via teachers' instructional and relational teaching behaviors, and (3) "recursive effects" back from student outcomes on teacher emotions, both directly and indirectly via teachers' appraisals of student outcomes and their correspondingly adapted teaching behaviors. We then present a tour d'horizon of empirical evidence from this field of research, highlighting valence-congruent links in which positive emotions relate to desirable outcomes and negative emotions to undesirable outcomes, but also valence-incongruent links. Last, we identify two key challenges for teacher emotion impact research and suggest three directions for future research that focus on measurement, research design, and an extended scope considering emotion regulation.