This study was an action research study that explored teacher's beliefs about student engagement and their role in student engagement through the development of a professional development innovation, the Transforming Student Engagement Professional Development program. This professional development program innovation was designed to lead participants through the stages of transformative learning theory and used the community of inquiry framework as the lens through which to explore student engagement strategies. A mixed-methods action research design was used to explore how participants transformed their feelings, beliefs, and assumptions around their online student engagement practices as they designed their online classroom as a community of inquiry. Pre/post Teacher Self Efficacy and Community of Inquiry surveys were used as well as a Learning Activities Survey and Interview. Study documents included calendars of training and agendas, participant journals, and my research memos. Participation in the Transforming Student Engagement Professional Development program resulted in significant changes in the participants' beliefs about student engagement, what their role in student engagement is, and their understanding and use of the Community of Inquiry framework as a lens through which to implement student engagement strategies. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]