The global burden of urolithiasis has attracted increasing attention, but there is still a lack of data on the trends and regional disparities of urolithiasis among young adults. Utilizing data from the Global Burden of Disease (GBD) 2021 Results Tool, this study analyzed annual incidence and disability-adjusted life years (DALYs) rates across 204 countries and 21 regions among young adults aged 15-49 years. Age-standardized rates (ASRs) were calculated to facilitate direct comparisons, and temporal trends were assessed using the Joinpoint Regression Program to determine average annual percentage changes (AAPC). The relationship between urolithiasis burden and the sociodemographic index (SDI) was evaluated through Spearman and Pearson correlation analyses. Globally, the number of incident cases rose from 34.6 million in 1990 to 50.7 million in 2021, while the ASR of incidence declined (AAPC: - 0.35%, 95% confidence interval[CI]: - 0.38% to - 0.29%). Similarly, the ASR of DALYs decreased (AAPC: -0.71%, 95% CI: -0.80% to - 0.62%). Males consistently exhibited higher ASRs than females, though both sexes showed declining trends. Regions with higher SDI values experienced decreasing burdens, while some low- and low-middle SDI regions saw increasing ASRs. In 2021, Eastern Europe recorded the highest ASRs of incidence and DALYs, whereas South Asia reported the highest absolute number of cases. A significant positive correlation was observed between SDI and ASR of incidence. These findings underscore the shifting global burden of urolithiasis among young adults, with a general decline in incidence and DALYs over the past three decades. However, the increasing trends in certain low SDI regions highlight the need for targeted public health interventions to address regional disparities.