Background <p>The metabolic score for visceral fat (METS-VF), which integrates measures of visceral adiposity, insulin resistance, and demographic variables, serves as a composite indicator of metabolic health. However, the association between METS-VF and atrial fibrillation (AF) risk is unclear. This study aimed to investigate the prospective association between METS-VF and incident AF within the UK Biobank cohort.</p> Methods <p>A total of 400,668 participants from the UK Biobank were included in the analysis. Flexible parametric survival models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between METS-VF and AF incidence. Additional subgroup and sensitivity analyses were conducted to evaluate the consistency of the results.</p> Results <p>Over a cumulative follow-up of 62,789,030 person-months, 28,764 individuals were diagnosed with AF. In multivariable-adjusted models, elevated METS-VF levels were significantly associated with a heightened risk of AF, with an adjusted HR of 1.38 (95% CI, 1.34–1.42). When stratified by METS-VF quartiles, the adjusted HRs for the second, third, and fourth quartiles were 1.08 (95% CI, 1.03–1.12), 1.14 (95% CI, 1.09–1.19), and 1.44 (95% CI, 1.37–1.50), respectively (P for trend &lt; 0.001). The association remained stable across multiple sensitivity analyses.</p> Conclusions <p>Elevated METS-VF is independently linked to a greater risk of incident AF. These findings underscore the potential utility of METS-VF as a clinical marker for early identification of individuals at elevated AF risk, supporting its role in targeted prevention and personalized cardiovascular risk management.</p> Clinical trial number <p>Not applicable.</p>