Background: Limited research has looked at the physical activity (PA) among Chinese children and adolescents with intellectual disabilities. Methods: The Children's Leisure Activities Study Survey-Chinese version was applied in evaluating PA levels among children and adolescents with intellectual disabilities. Results: The data indicated that only 29.5% of children and adolescents with intellectual disabilities met the PA recommendation. Boys engaged in significantly more MVPA and had higher energy expenditure than girls during weekdays and the whole week. The general trend in PA levels demonstrated a downtrend with the growth of age of children and adolescents with intellectual disabilities. The students aged 6-12 years old performed more MVPA and had greater energy expenditure compared with those 13-15 and 16-18 years old. Conclusion: The level of PA among Chinese children and youths with intellectual disabilities is remarkably low, and there is a large gap compared with the PA recommendation.