Background and ObjectivesTo estimate the rates of incidence, death, and disability-adjusted life years (DALYs) of ischemic stroke in young adults aged 15–49 years and the relevant risk factors by sex, age group, and sociodemographic index (SDI) in 204 countries and territories.MethodsData from the Global Burden of Diseases, Injuries, and Risk Factors (GBD) 2019 study were used. The estimated annual percentage changes (EAPCs) were calculated to evaluate the temporal trends from 1990 to 2019. We also estimated the risk factors contributing to DALYs resulting from ischemic stroke.ResultsFrom 1990 to 2019, the global age-standardized incidence (EAPC = −0.97), death (EAPC = −0.11), and DALYs rates (EAPC = −0.55) of ischemic stroke in young adults decreased. The largest increases in age-standardized incidence, death, and DALYs rates were observed in the low and low-middle SDI quintiles. At the regional level, North Africa and the Middle East and Southeast Asia showed the largest increases in the age-standardized incidence, death, and DALYs rates of ischemic stroke. The age-standardized incidence rate was higher among young women than among young men in 2019. Globally, a high environmental temperature, high body mass index (BMI), and a high fasting plasma glucose contributed to the largest increases in age-standardized DALYs rates between 1990 and 2019. In the same period, the largest increases in the age-standardized DALYs rates in high-SDI and low-SDI regions were attributable to high environmental temperatures and alcohol use, respectively.DiscussionThe burden of ischemic stroke in young adults continues to increase in low-SDI regions such as North Africa and the Middle East and Southeast Asia. There were differences in the primary risk factors related to the burden of ischemic stroke in different SDI regions. Targeted implementation of cost-effective policies and interventions is an urgent need to reduce the burden of ischemic stroke in young adults.