Chronic ankle instability (CAI) is a condition characterized by recurrent sprains and "giving way" of the ankle. Studies report high school athletes have higher risk of developing CAI and CAI patients frequently exhibit balance problems, but little is known about these deficits in adolescents with CAI. The purpose of the study was to identify differences in static and dynamic postural control between physically active high school adolescents with and without CAI. High school athletes with and without CAI completed the Balance Error Scoring System with SWAY mobile balance software and Y-Balance Test including weight-bearing lunge test as a subtest across the four local high school student-athletes. Twenty-five (Control: 13, CAI: 12) student-athletes participated in the study. CAI was defined as a history of lateral ankle sprain and a score of <27 on the Cumberland Ankle Instability Tool-Youth (CAIT-Youth). There were no significant differences between groups (p > 0.05) in any of the SWAY balance tasks and composite scores during eyes-open or eyes-closed session. There were significant differences between groups for Y-balance composite scores (p = 0.01) and normalized scores for the anterior (p = 0.02) and posterolateral directions (p = 0.02), whereas no significant difference between groups for the posteromedial direction (p = 0.12). The results imply different aspects of balance control strategy and relevant differences in this population compared to those of adults. Therefore, athletic trainers and other health care providers should provide customized treatment and rehabilitation to improve balance control deficits in this population.