Background <p>Tinnitus is a prevalent auditory disorder that significantly affects quality of life, with emerging evidence suggesting a connection between metabolic dysregulation and tinnitus pathogenesis. The Atherogenic Index of Plasma (AIP), a marker of atherogenic lipid metabolism, has been associated with cardiovascular disease risk but remains underexplored in the context of tinnitus.</p> Objective <p>This study aimed to investigate the relationship between AIP and tinnitus prevalence in U.S. adults, and to further examine whether hypertension mediates this association.</p> Methods <p>We analyzed data from 2,464 participants in the National Health and Nutrition Examination Survey (NHANES, 2005–2012). Tinnitus status was determined by self-report, and AIP was calculated as log10(triglycerides/HDL-C). Multivariable logistic regression models were used to assess the association between AIP and tinnitus. Stratified analyses and mediation analysis were conducted to explore effect modification and the mediating role of hypertension. Hypertension was defined as a self-reported physician diagnosis or use of antihypertensive medication.</p> Results <p>Elevated AIP was significantly associated with an increased risk of tinnitus in a dose–response manner (fully adjusted OR = 1.73, 95% CI: 1.19–2.52, P = 0.01). Stronger associations were observed in younger participants, females, non-Hispanic Whites, and smokers. Mediation analysis showed that hypertension partially mediated the association between AIP and Tinnitus, accounting for 17.53% of the total effect.</p> Conclusions <p>Higher AIP is associated with greater tinnitus prevalence, with hypertension serving as a partial mediator. These findings highlight the potential value of AIP as a metabolic biomarker for tinnitus risk stratification and emphasize the importance of managing metabolic dysregulation in tinnitus prevention.</p>