Executive function refers to a set of cognitive processes involved in goal-oriented behavior—especially inhibition, attention shifting, and working memory. In Down syndrome, there was an established weakness in executive function but the exact nature of the weakness was not well established. Executive functions are associated with a host of important outcomes, so it is important to understand executive function ability in Down syndrome. The current meta- analysis included 57 studies that compared a group with Down syndrome to a typically developing mental age matched group on at least one executive function task. Overall, individuals with Down syndrome performed significantly poorer on EF tasks than their typically developing mental age matched peers. Inhibition was a relative strength in the executive function profile, but it is still a weakness compared to the matched groups. There was a medium to large effect size across all executive functions but effect sizes may have been restricted due to skew. Implications for interventions and future research are discussed.