Background <p>Monkeypox (mpox) has emerged as a global public health concern, particularly among men who have sex with men (MSM). Stigma limits access to care, and the role of social support in shaping care-seeking through psychosocial mechanisms remains unclear. This study examined whether social support influences care-seeking intentions via stigma and perceived healthcare benefits among MSM in China.</p> Methods <p>A cross-sectional study was conducted from October 2023 to March 2024 across 6 provinces in China. Descriptive statistics, chi-square tests, Spearman correlations, and logistic regression were performed to explore associations between HBM-related constructs and healthcare-seeking intentions. Structural equation modeling was used to examine the direct and indirect effects of social support via stigma and perceived healthcare benefits.</p> Results <p>Among participants, 83.4% expressed an intention to seek healthcare for mpox. Directly, social support was positively associated with healthcare-seeking intention (β = 0.274, p &lt; 0.001). Indirectly, social support affected healthcare-seeking intention through two pathways: (1) by reducing stigma (β = −0.108, p &lt; 0.001), which in turn enhanced perceived healthcare benefits (β = −0.663, p &lt; 0.001), ultimately increasing healthcare-seeking intention (chain effect β = 0.033, p = 0.005); and (2) directly enhancing perceived healthcare benefits (β = 0.091, p &lt; 0.001), thereby increasing healthcare-seeking intention (β = 0.231, p &lt; 0.001; indirect effect β = 0.042, p = 0.005). The total indirect effect accounted for 22.6% of the total effect.</p> Conclusions <p>Social support enhances mpox care-seeking intention among MSM in China by reducing stigma and improving perceptions of privacy, affordability, and treatment efficacy. Integrated interventions—combining peer support, stigma reduction, and privacy protection—are needed to foster early health engagement.</p>