This systematic review examined multiple indicators of adolescent students’ engagement in school, and the indicators’ associations with teacher–student relationships (TSRs). Seven psychology, education, and social sciences databases were systematically searched. From this search, 46 published studies (13 longitudinal) were included for detailed analysis. Cross-sectional studies showed better quality TSRs were associated with enhanced engagement in school. These associations with TSRs were demonstrated among multiple indicators of student engagement (i.e., psychological engagement, academic grades, school attendance, disruptive behaviors, suspension, and dropout). Similar associations were found in longitudinal studies. Longitudinal and cross-sectional associations remained when covariates from the individual, family, school, and teacher contexts known to influence student engagement were controlled for. TSRs were shown to have an important but not exclusive role in their association with a comprehensive range of indicators of student engagement.