Purpose <p>Parents of children with attention-deficit/hyperactivity disorder (ADHD) often experience heightened levels of parenting stress. Although previous studies have established associations between affiliate stigma, perceived social support, and parenting stress, the potential mediating role of perceived social support in this relationship remains unclear. This study aimed to examine the relationships among affiliate stigma, perceived social support, and parenting stress, and to explore whether perceived social support mediates the relationship between affiliate stigma and parenting stress in parents of children and adolescents with ADHD.</p> Methods <p>A cross-sectional design was used. A total of 376 parents completed the 22-item Affiliate Stigma Scale (ASS), the Multidimensional Scale of Perceived Social Support (MSPSS), and the Parenting Stress Index–Short Form (PSI-SF). Structural equation modeling and bootstrapping procedures using IBM SPSS Amos 26.0 were conducted to test the hypothesized mediation model.</p> Results <p>Affiliate stigma was negatively correlated with perceived social support (<i>r</i> = -0.288, <i>p</i> &lt; 0.01) and was positively correlated with parenting stress (<i>r</i> = 0.464, <i>p</i> &lt; 0.01). Additionally, perceived social support was negatively correlated with parenting stress (<i>r</i> = -0.457; <i>p</i> &lt; 0.01). Perceived social support mediated the relationship between affiliate stigma and parenting stress (β = 0.156, B = 0.209, SE = 0.029, 95% bias-corrected bootstrap <i>CI</i>: 0.104 to 0.219).</p> Conclusion <p>Perceived social support may serve as a protective factor that buffers the negative impact of affiliate stigma on parenting stress. Interventions aimed at reducing stigma and enhancing multi-dimensional social support are recommended for parents of children with ADHD.</p>