This study conducted a comprehensive comparison of social cognitive ability in participants with Autism spectrum disorder (ASD) and schizophrenia (SCZ) to aid efforts to develop effective intervention programs. Participants with both ASD and SCZ performed worse than typically developing controls, and there were very few differences between the two clinical groups. Also the strength of the relationship between neurocognitive and social cognitive performance was of similar, moderate size for ASD and SCZ. Findings largely suggest comparable levels of social cognitive impairment in ASD and SCZ, which may support the use of existing social cognitive interventions across disorders. However, future work is needed to determine whether the mechanisms underlying these shared impairments are also similar, or if these common behavioural profiles may emerge from different pathways.