Background <p>Arthritis is a prevalent condition among older adults, potentially influenced by environmental exposures. However, evidence on the relationship between household mold exposure and arthritis in aging populations remains limited.</p> Methods <p>This study utilized data from the 2014 wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Logistic regression models estimated the association between mold exposure and arthritis, adjusting for demographic, lifestyle, and health-related covariates. Subgroup and interaction analyses explored potential effect modifiers. In the first sensitivity analysis, 1:2 propensity score matching (PSM) was applied to improve covariate balance, while the second (2018 wave) additionally adjusted for indoor ventilation, vitamin supplementation, and analgesic use.</p> Results <p>The prevalence of arthritis was 13.2%. Among older Chinese adults, participants with arthritis were more likely to be younger, female, reside in city, engage in physical activity, have higher BMI, and report mold exposure. Mold exposure was associated with higher odds of arthritis (Model 1: OR = 1.32, 95% CI: 1.05–1.65; Model 2: OR = 1.36, 95% CI: 1.08–1.71), and the association persisted after PSM (Model 1: OR = 1.33, 95% CI: 1.03–1.71; Model 2: OR = 1.34, 95% CI: 1.03–1.73). Drinking status significantly modified this relationship (<i>P</i> for interaction &lt; 0.05). Sensitivity analyses confirmed robustness of the association between mold exposure and arthritis, and analgesic use was additionally found to be associated with arthritis.</p> Conclusions <p>Our findings indicate that both mold exposure and analgesic use are associated with an increased likelihood of arthritis in older adults, underscoring the need to improve damp and deteriorating housing conditions and to promote the rational use of analgesics to support healthy aging.</p>