Background: The protective effects of social support for caregiver mental health are well documented, however the differential impact of support providers (partner, child, family, siblings, friends, professionals) and types (perceived, received) remain unclear. Methods: Observational data from 21 independent studies, involving a pooled sample of 2273 parents, stepparents and grandparents of children (aged ≤ 19) with autism spectrum disorder (ASD) were examined. Pearson's r, publication bias and heterogeneity were calculated using random effects modelling.