Introduction Oral disorders are among the most prevalent diseases globally, yet their burden in Southeast Asia remains poorly characterized. Understanding regional patterns is critical for health planning and prevention. Methods We analysed data from the Global Burden of Disease 2021 study to assess the prevalence, incidence, and disability-adjusted life years of oral disorders across the 10 Association of Southeast Asian Nations (ASEAN) member states from 1990 to 2021. Indicators were age-standardized and analysed by sex, age, country, and socio-demographic index. Results Oral disorders accounted for nearly half of all-cause prevalence and around 1% of total disease burden in 2021. From 1990 to 2021, prevalent cases rose by over 50% and incident cases by more than 30%, while age-standardized rates showed slight declines. Population growth and ageing were the primary drivers of these increases. Caries of permanent teeth contributed the largest share, followed by periodontal disease and edentulism. Higher socio-demographic index correlated with lower overall burden but a higher proportion of periodontal disease. These findings indicate that oral health remains a major source of morbidity across ASEAN despite modest epidemiologic improvement. Demographic pressures continue to offset gains from prevention and care. Conclusions Expanding prevention and primary oral healthcare – including sugar reduction, fluoridation, and sealant or varnish programs – could substantially reduce disability and unmet need. Routine regional surveillance using harmonized indicators is essential to guide equitable policy and investment within the post-2025 ASEAN health agenda. © 2025 The Authors.