Stigma towards people living with HIV is pervasive in China and related to poor service utilization, psychosocial distress and diminished quality of life (QOL). In an effort to identify mechanisms to reduce HIV stigma and its negative consequences, we examined whether social support mediates the relation between enacted stigma and both depressive symptoms and QOL among 120 HIV outpatients in Beijing, China. Generally, perceived social support was associated with less stigma, less depressive symptomatology and better QOL. Using multivariable regression models, we found that social support was a full mediator of the impact of stigma on both depressive symptomatology and QOL. The findings suggest social support may be an important target of interventions to reduce the impact of stigma on poor psychosocial health outcomes.