Background: Static and dynamic balance skills can be related to the activities of daily living (ADL) in children with non-syndromic intellectual disabilities, and the type of balance skills affecting ADL can differ depending on the domain of ADL (self-care, mobility, and social function). Methods: The ADL capabilities of 66 children with intellectual disabilities were assessed using the Pediatric Evaluation of Disability Inventory (PEDI) and were examined in relation to static and dynamic balance skills. Results: Significant positive correlations were found between the one-leg standing and PEDI (r = 0.841 for self-care, r = 0.700 for mobility, and r = 0.760 for social function). Our analysis showed that static balance skills affected self-care, dynamic balance skills affected mobility, and intelligence quotient affected social function. Conclusions: Improving balance skills is important for enhancing ADL capabilities, and the type of balance skills that need enhancement vary based on the domain of ADL.