Affiliate stigma is one risk factor for psychological distress in familial caregivers. Few studies however, and none involving caregivers in the UK and US, have explored caregivers’ characteristics and family constellation variables as risk and protective factors for affiliate stigma. This study aimed to fill this gap. Moreover, we believe this study is only second to explore these relationships among caregivers of children with autism spectrum disorder (ASD), a group particularly vulnerable to affiliate stigma. A sample of n=192 caregivers of children with ASD completed an online survey assessing caregivers’ characteristics and family factors, and affiliate stigma. Non-partnered caregivers were more likely to report affiliate stigma, as were caregivers with shorter sleep duration. These findings might help clinicians and other health professionals identify caregivers at risk for affiliate stigma and concomitant psychological distress.