The purpose of this study was to examine how clinical supervision impacted School Counselor self-efficacy in a sample of certified School Counselors. Using the School Counselor Self-Efficacy Scale, this study compared the averages of scores between School Counselors who did not have clinical supervision and School Counselors who had clinical supervision within the last five years for a period of six months or more. This study also used interviews to explore School Counselors' perception of the impact of clinical supervision on their School Counselor Self-Efficacy Scale scores. Participating School Counselors who engaged in clinical supervision had a higher mean score on the School Counselor Self-Efficacy Scale than those School Counselors who did not engage in clinical supervision. Qualitative interviews with School Counselors who engaged in clinical supervision yielded four themes that describe the perceived relationship between clinical supervision and self-efficacy: confidence, growth professionally/ school counselor identity, perspective, and holistic approach. This study strengthens the argument for implementation of clinical supervision for School Counselors. [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.]