Low student classroom engagement is alarming. I describe how autonomy, competence, and relatedness developed through extracurricular activities shape classroom engagement. Using a qualitative descriptive design, I interviewed fourteen purposively selected students and applied thematic analysis. I found that the roles of autonomy, competence, and relatedness in developing classroom engagement involve strengthening students' self-discipline, skill mastery, and supportive relationships. Teachers may strengthen classroom engagement through collaborative activities and professional development initiatives. Future studies may utilize Multiple Linear Regression Analysis to predict classroom engagement, and Exploratory Factor Analysis (EFA) to develop and validate instruments based on the identified themes.