Despite an increase in special education enrollment, a stark gap in high school completion between students with and without disabilities persists. This study examined the impact of Unified Champion Schools (UCS), a Special Olympics program designed to foster social inclusion through three components--Unified Sports, Inclusive Youth Leadership, and Whole School Engagement--on high school graduation rates. Using a novel dataset and a difference-in-differences design, we found that implementing the UCS program increased the graduation rate by 1.1 percentage points for all students and 1.4 percentage points for students with disabilities. The increase in schooling outcomes for students with disabilities in UCS schools also was found to be positively correlated with perceptions about a more socially inclusive school environment.