Background: Children with intellectual disability (ID) experience high levels of mental health problems that may require access to professional support. However, there is limited information about how frequently these children access services. Method: A survey of mental health in children living in the United Kingdom (UK) by the Office of National Statistics in 2004 (N = 7,977) was used to examine levels of service access. Children with ID and mental health problems were compared to children with mental health problems (without ID), children with ID and no mental health problems, and typically developing children. Results: Children with ID and mental health problems accessed specialist mental health services at higher rates than children with only ID, but at similar rates to children who only have mental health problems. Conclusions: Overall, low levels of service access highlight likely high unmet need among children with ID, mental health problems, and both conditions.