Abstract Oral cancer, the 13th most common globally, is primarily squamous cell carcinoma linked to tobacco, alcohol, and HPV. Despite advances in care, it remains a major health concern due to high mortality and its impact on quality of life. This study analyzed socio-demographic disparities in oral cancer burden using data from 1990 to 2021. We analyzed annual incidence, mortality, and DALYs across 204 countries, using age-standardized rates and the Socio-demographic Index (SDI) to assess development-related impacts. Statistical methods included Kruskal–Wallis tests, linear regression, joinpoint regression for trends, and Exponential Smoothing for forecasts (2022–2030), with analyses conducted in STATA and Python, and p < 0.05 as significant. Incidence was highest in high SDI countries, while mortality and DALYs were highest in low and middle SDI countries (p < 0.001). From 1990 to 2021, incidence increased (AAPC: 0.5–1.0%), while mortality (APC: − 0.5%) and DALYs (APC: − 0.6%) declined in low SDI regions. Significant disparities across SDI categories (p < 0.001) showed incidence rising with socio-demographic development (R2 = 0.102, p < 0.001), with high-middle SDI regions bearing the highest mortality and DALYs. These findings highlight the need for awareness, prevention, early detection, and accessible care, especially in lower SDI regions.