Background: The purpose of this study was to investigate the effects of plyometric training on balance, joint position sense, and explosive strength in young taekwondo athletes. Methods: A total of 20 taekwondo athletes aged between 15 and 18 years voluntarily participated in the study. Participants were randomly assigned to an experimental group (n = 10; 5 females, 5 males) and a control group (n = 10; 5 females, 5 males). In addition to regular taekwondo training, the experimental group performed a plyometric training program three times per week for eight weeks, while the control group continued only their regular training. A 2 × 2 mixed-design (group × time) was employed. A two-way repeated measures ANOVA was conducted to examine the main effects of group (experimental vs. control) and time (pre-test vs. post-test), as well as the group × time interaction effect. Results: The Significant group × time interaction effects were observed for eyes-open balance (EOB), eyes-closed balance (ECB), standing long jump (SLJ), vertical jump (VJ), dominant 30° knee joint position sense, and non-dominant 45° knee joint position sense (p < 0.05), indicating that changes over time differed between the experimental and control groups for these variables. No significant interaction effects were found for dominant 45°, dominant 60°, non-dominant 30°, and non-dominant 60° (p > 0.05), suggesting similar changes over time in both groups. A significant main effect of time was observed for EOB, ECB, SLJ, and VJ (p < 0.05), while the main effect of group was significant for SLJ and non-dominant 45° (p < 0.05). Conclusion: An 8-week plyometric training program led to significant improvements in balance (EOB, ECB) and explosive performance (SLJ, VJ), as well as in selected knee joint position sense variables (dominant 30° and non-dominant 45°), as indicated by significant group × time interaction effects. No significant effects were observed for dominant 45°, dominant 60°, non-dominant 30°, or non-dominant 60°. The significant interaction observed at the non-dominant 45° angle suggests that changes over time differed between groups, although baseline variability may have contributed to this difference. Trial registration: Registration date: [29.12.2025] (ClinicalTrials.gov ID: NCT07351539).