Background: Extremely high rates of mortality and morbidity have been reported among people with intellectual disabilities. Virtually no research has addressed the potential social determinants of health status within this very vulnerable population. Method: Cross-sectional survey of self-reported health status and indicators of socioeconomic disadvantage and social connectedness in 1273 English adults with mild or moderate intellectual disabilities. Results: Indicators of socioeconomic disadvantage accounted for a statistically significant proportion of variation in health status, over and above any variation attributable to the personal characteristics and living circumstances of participants. Indicators of social participation and networks did not add to the explanatory power of the model. Among the indicators of socioeconomic disadvantage, hardship was more strongly associated with variation in health status than either employment status or area-level deprivation. Conclusion: As in the general population, self-reported health was associated with indicators of socioeconomic disadvantage, especially hardship. In contrast, there was no evidence of any association between health status and social participation and networks.