We examined the contribution of socioeconomic position to the health and mental health status of children and adolescents with intellectual disabilities in a sample of 10,438 British children. Intellectual disability was a significant risk factor for poorer general health, OR = 4.5, emotional disorders, OR = 2.0, and conduct disorders, OR = 7.7. Between-group differences in socioeconomic position and household composition, however, accounted for 24% of the increased risk of poor health, 23% of the increased risk for conduct disorder, and 37% of the increased risk for emotional disorder. We concluded that socioeconomic disadvantage may account for a significant proportion of the increased risk for poorer health and mental health of children and adolescents with intellectual disabilities.