Metabolic syndrome (MetS), a cluster of conditions including abdominal obesity, high blood pressure, and abnormal blood sugar and lipid levels, is a growing global health concern, yet its global burden remains poorly characterized. Here we show trends in MetS prevalence from 2000 to 2023, based on a systematic review and Bayesian modelling of 3236 data points with 45,549,151 adults. Between 2000 and 2023, prevalence rose from 14.7% (13.1–16.7) to 31.0% (28.5-33.9) among women, and from 9.0% (6.9–12.1) to 25.7% (21.5–31.1) among men. In 2023, an estimated 1.54 billion adults (1.35–1.76) had MetS globally: 846 million (776–924) women and 692 million (579–837) men. Prevalence increased with age, urbanicity, and income level, ranging from 7.5% to 45.0% among women and 6.5% to 59.6% among men across regions. Among both women and men, prevalence increased in 196 countries and territories. These findings call for targeted interventions to address the rising global burden.