Background: Identifying past, present, and future temporal trends in gallbladder and biliary tract cancer (GBTC) can increase public awareness and promote changes in prevention and treatment strategies. Methods: The incidence and death rates of GBTC between 1990 and 2021 were extracted from the Global Burden of Disease study 2021 and assessed according to country, region, year, age, and sex. Time trends were measured using the average annual percentage change (AAPC) and projections of the burden of disease for 2022 to 2045 were made using the Bayesian age-period-cohort model. Results: In 2021, there were 216,768.3 new cases (95% uncertainty interval [UI], 181,888.0-245,237.6) and 171,961.2 deaths (95% UI,142,351.8-194,238.4) in GBTC globally. The increases in incidence and deaths were 101.09% and 74.26%, respectively, compared with 1990. The GBTC burden was higher in females and older adults. However, age-standardized incidence rate (ASIR) and age-standardized death rate (ASDR) trended downward from 1990 to 2021, with AAPC at -0.39 (95% CI, -0.52 to -0.26) and -0.88 (95% CI, -0.96 to -0.79), respectively. Although the ASIR and ASDR for both sexes are projected to decline gradually from 2022 to 2045, the incidence and deaths are expected to increase steadily. In addition, the global proportion of GBTC deaths owing to high body mass index in 2021 was 12.66% for females and 10.48% for males, which did not change significantly from 1990. Conclusion: GBTC is becoming a major global health burden, especially among females and older adults. Given the increasing burden of an aging population, there is a need to reduce the incidence of this disease by adopting effective strategies and measures targeting risk factors. (c) 2025 Society for Surgery of the Alimentary Tract. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.