Individuals with autism spectrum disorder (ASD) often benefit from allied health services such as occupational therapy, speech and language pathology, and applied behavioral analysis. While there is consistent evidence of disparities in access and use of medical services (e.g. dentistry), no such systematic review has examined disparities and differences in allied health use amongst children with ASD. In this systematic review, we examine disparities and differences in service access and use for children with ASD. Our findings suggest that children who are older, have less severe ASD symptoms, are from minority groups, and those from particular geographic regions are less likely to receive allied health services. Limitations and future directions are discussed.