Context: Athletes with intellectual disability (ID) have a high risk of injury while participating in various sports. Warm-up (WU) is the most preventive measure to reduce injuries in sports. Objective: To investigate the effects of dynamic stretching WU (DS-WU) and plyometric WU (PL-WU) on dynamic balance in athletes with ID. Design: Crossover study. Setting: Research laboratory. Participants: A total of 12 athletes with ID (age 24.5 [3.22] y, height 165.7 [8.4] cm, weight 61.5 [7.1] kg, intelligence quotient 61.1 [3.5]). Main Outcome Measures: Dynamic balance was assessed using the Star Excursion Balance Test (SEBT) at pre-WU, post-WU, and 15 minutes post-WU for both the DS-WU and the PL-WU. A 2-way analysis of variance (3 sessions × 2 WU methods) with repeated-measures was used in this study. Results: Following the DS-WU, participants demonstrated significant improvements in the SEBT composite score post-WU (89.12% [5.54%] vs 87.04% [5.35%]; P < .01) and at 15 minutes post-WU (89.55% [5.28%] vs 87.04%, P < .01) compared with pre-WU. However, no significant difference between these two post-WU scores (post-WU and 15 min post-WU) was found. For the PL-WU, participants demonstrated a significant decrease in the SEBT composite score at post-WU (85.95% [5.49%] vs 87.02% [5.73%]; P < .05); however, these scores increased significantly at 15 minutes post-WU (88.60% [5.42%] vs 87.02% [5.49%]; P < .05) compared with that at pre-WU. The SEBT composite scores are significantly higher in the DS-WU than in the PL-WU at both post-WU sessions (P < .05). Conclusion: Both DS-WU and PL-WU could improve dynamic balance and may be recommended as WUs in athletes with ID; however, particular caution should be exercised immediately after the PL-WU.