Many educational systems are generally viewed across the United States as failing to meet the increased demand of preparing an educated workforce to sustain the nation's economy and overall citizen way of life. One such failing is represented in the number of students not completing high school. To address the systemic dropout problem, federal and state government accountability measures have been put into place to focus on identified students labeled as at-risk of dropping out of high school. Local school districts consistently allocate personnel and funds to address these identified at-risk students and to connect the students with the learning environment, thus keeping them engaged in the educational process. Multiple studies have identified engagement as a key factor to high school completion among at-risk students; however, there are limited studies involving Texas high students identified as at-risk and their participation in extracurricular activities as a contributing factor to subsequent student success. The purpose of this study was to consider the presumed associated difference between at-risk student success, as determined by attendance, grade point average, and frequency of disciplinary infractions, and at-risk student participation in extracurricular activities in one large, traditional north Texas high school. A mixed methods research study involving identified at-risk students in grades nine through 12 was performed utilizing historical data from the 2017-2018 and 2018-2019 academic years as well as interviews with campus administrators, coaches/sponsors, and counselors to understand the significance of the impact extracurricular activity participation on at-risk student academic and behavioral success. A Mann-Whitney "U" analyses of the historical data found that at-risk students who participate in extracurricular activities experience higher average daily attendance rates, improved grade point averages, and reductions in lost instructional time due to disciplinary infractions at a statically significant level. Finally, analyses of conducted interviews revealed that the perceptions of educational leaders on the focus high school campus was that strong mentor relationships built through extracurricular participation had the greatest impact on at-risk student success. [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.]