ObjectiveTo systematically analyze the temporal trends in the burden of gallbladder and biliary tract cancer (GBTC) in Yunnan Province, China, from 1990 to 2021 using the Global Burden of Disease Study 2021 (GBD 2021), and to project the disease burden through 2030 to inform regional prevention and control strategies. MethodsData on crude prevalence, mortality, and disability-adjusted life year (DALY) rates for GBTC in Yunnan Province, China, from 1990 to 2021 were extracted from GBD 2021. Temporal trends in the age-standardized prevalence, mortality, and DALY rates (ASPR, ASMR, and ASDR) were analyzed using Joinpoint regression models, and the average annual percent change (AAPC) was calculated. Furthermore, the Bayesian age-period-cohort (BAPC) model was employed to project the disease burden from 2022 to 2030. ResultsFrom 1990 to 2021, the crude prevalence, mortality, and DALY rates of GBTC in Yunnan Province increased from 1.01/100 000, 1.00/100 000, and 27.50/100 000 in 1990 to 3.00/100 000, 1.78/100 000, and 43.29/100 000 in 2021, respectively. After age standardization, the ASPR showed an upward trend (AAPC=1.29%), whereas the ASMR (AAPC=–0.58%) and ASDR (AAPC=–0.70%) exhibited downward trends. Regarding sex disparities, the increase in ASPR was more pronounced in males than in females (AAPC: 1.88% vs. 0.67%), while the declines in ASMR and ASDR were less steep in males than in females (ASMR AAPC: –0.20% vs. –0.92%; ASDR AAPC: –0.29% vs. –1.06%). Age-stratified analysis revealed that the ASPR increase was most prominent in the 30–34-year age group (AAPC=2.63%), and the reductions in ASMR and ASDR were most substantial in the 50–59-year age group (AAPC: –1.20% and –1.18%, respectively). Projections based on the BAPC model indicate that by 2030, the ASPR will continue to rise to 3.17/100 000, whereas the ASMR and ASDR are projected to decline gradually to 1.44/100 000 and 34.86/100 000, respectively. ConclusionsThe absolute disease burden of GBTC in Yunnan Province keeps rising. While the ASMR and ASDR have shown a declining trend, the steady growth in the ASPR points to a substantial accumulation of prevalent cases. Future public-health programmes should prioritise targeted early-detection and treatment strategies for the young- and middle-aged population.