Academic engagement is one of the key predictors for success in school. Disengaged students have a much higher likelihood of dropping out, becoming incarcerated or becoming dependent on social services in their future. Teacher behavior has a significant impact on the levels of student engagement in the classroom. Self-determination Theory (SDT) suggests that when students feel that their psychological needs of competence, emotional connection to others, and autonomy are met, students will be much more likely to be engaged in school. For adolescent students, fostering a sense of autonomy seems to be the most important psychological need. The focus of this action research was to use collaborative inquiry groups to change teacher practice to become more autonomy supportive in order to increase student engagement in the classroom. Collaborative inquiry groups have been shown to not only change teacher practice because they can meet teachers’ psychological needs of competence, relatedness and autonomy, but also serve as a model of the type of autonomy supportive conditions that teachers can implement that would lead to increased engagement in the classroom. Teachers followed a collaborative inquiry model where they spent time defining the problem, conducting research and gathering data to develop an intervention plan, implementing the plan, reflecting and refining the plan, and then celebrating and sharing their achievements and learning with the larger school community. As a result of the collaborative inquiry group, teachers developed a common understanding of the causes of student engagement, they became more reflective, and their practice improved and became more autonomy supportive. In addition, all teachers reported an increase in student engagement in their classrooms as a result of the intervention strategy.