Background <p>The incidence and mortality of kidney cancer vary widely globally. This study aims to examine the global burden and trends of kidney cancer from 1990 to 2021 and its associations with various factors.</p> Methods <p>Data on kidney cancer cases and age-standardized rates (ASRs) of incidence, prevalence, mortality, and disability-adjusted life years (DALYs) from 1990 to 2021 were collected and analyzed globally. The age-period-cohort (APC) and Bayesian age-period-cohort (BAPC) models were used to track disease burden dynamics and predict future trends.</p> Results <p>Globally, the incidence of kidney cancer increased from 1.6 × 10⁵ in 1990 to 3.9 × 10⁵ in 2021. China had the most cases, deaths and DALYs in 2021, followed by the United States. Cabo Verde had the fastest growth in ASRs, whereas Southern Latin America had the highest ASRs. Forty-nine countries or regions, mainly in Western Europe and North America, had a decreasing trend in ASR for mortality over the period. Overall, the burden of kidney cancer increased with a higher sociodemographic index (SDI). The APC and BAPC models predicted a steady decline in the ASRs for incidence, prevalence, mortality and DALYs for kidney cancer over the next 20 years. High body mass index (BMI) and smoking were major risk factors, with high BMI being prominent in low-SDI countries.</p> Conclusions <p>From 1990 to 2021, the global burden of kidney cancer represented a significant health threat. Policies to reduce exposure to risk factors could be beneficial amid global aging trends.</p>