While there is evidence to support the notion that extracurricular activities have a positive impact on student success and development, the reasons "why" students participate in these activities, why they continue to participate in these activities, and "why" these activities lead to better educational outcomes are unclear. This study was conducted at three high schools in a county in northeast Florida with a total n of 131 students. This study used three theories as lenses to examine how student-teacher relationships impacted student engagement in extracurricular activities and in turn student achievement: Self-Systems Processing (Connell & Wellborn, 1991), Attachment Theory (Bowlby, 1969), and School Belonging (Goodenow & Grady, 1993) to analyze the data collected from the surveys. This data collection for this study included both quantitative survey questions and open-ended qualitative survey questions that produced three main findings. First, overall, students involved in extracurricular activities had slightly higher mean-level perceptions about their student-teacher relationships (i.e., caring, trust, and help) than those not involved in extracurricular activities, but this difference was not statistically significant. Second, for students involved in extracurricular activities their perceptions of the student-teacher relationship were slightly higher for their extracurricular teachers than their general teachers, but again, not significantly so. Finally, there were no effects of extracurricular activity on academic achievement within this sample. [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.]