Abstract Background Acne vulgaris is a common skin condition affecting adolescents and young adults worldwide, yet data on the burden and trends of this disease remain limited. We aimed to investigate trends in the burden of acne vulgaris among adolescents and young adults aged 10–24 years at global, regional and national levels. Methods We retrieved data from the Global Burden of Disease Study 2021 for individuals aged 10–24 years in 204 countries and territories from 1990 to 2021. We analysed the numbers, age-standardized rates and average annual percentage changes (AAPCs) of the prevalence, incidence and disability-adjusted life years (DALYs) for acne vulgaris at the global, regional and national levels. Additionally, we examined these global trends by age, sex and Sociodemographic Index (SDI). Results Globally, the age-standardized prevalence rate of acne vulgaris among adolescents and young adults increased from 8563.4 per 100 000 population [95% uncertainty interval (UI) 7343.5–9920.1] in 1990 to 9790.5 (95% UI 8420.9–11 287.2) per 100 000 population in 2021, with an AAPC of 0.43 [95% confidence interval (CI) 0.41–0.46]. The age-standardized incidence rate and age-standardized DALY rate also showed a similar upward trend. Regionally, Western Europe had the highest age-standardized prevalence, incidence and DALY rates, while North Africa and the Middle East had the largest increase in these rates. By SDI quintile, the high SDI region had the highest age-standardized prevalence, incidence and DALY rates from 1990 to 2021, whereas the low-middle SDI region had the lowest burden of acne vulgaris but experienced the most significant increase in these rates. Globally, the age-standardized prevalence rate of acne vulgaris in 2021 was approximately 25% higher in young women than in young men (10 911.8 per 100 000 population vs. 8727.8 per 100 000 population). Among all age groups, adolescents aged 15–19 years had the highest age-specific prevalence rate, while adolescents aged 10–14 years experienced the largest increase from 1990 to 2021 (AAPC 0.50, 95% CI 0.48–0.52). Conclusions The burden of acne vulgaris among adolescents and young adults has continued to increase in nearly all countries since the 1990s. Managing this condition remains a significant challenge, necessitating more effective and targeted interventions to control the acne burden.