Sex differences in autism may in part be understood by an atypical sex profile of executive function and non-executive function. In this study, we compared females and males with autism against non-autistic individuals on neuropsychological and self-report measures to examine whether any sex differences in executive function and non-executive function might be unique to autism. Our study showed a significant overall female advantage for measures of psychomotor speed, cognitive flexibility, verbal learning and memory and semantic fluency. There was no significant interaction effect between diagnosis and sex. No sex differences were observed on the self-report measure of executive function. Our results suggest that while females show different cognitive performance to males, these sex differences were not specific to the autistic cohort. Lay abstract Research comparing females and males with a diagnosis of autism suggests that there are sex differences in some characteristics such as behaviour regulation. One area not studied in detail is whether females and males with autism perform differently in tests of cognitive ability. The results of previous research are quite mixed. One explanation may be that some research comparing females and males with autism did not include a neurotypical control group for comparison. As a result, it is not clear whether the sex differences in cognitive ability observed in people with autism are similar to differences between neurotypical males and females. To better understand whether there are unique differences between males and females with autism, it is important to also compare them with neurotypical males and females. In our research, we included a neurotypical group and compared males and females with and without a diagnosis of autism. We found that the sex differences in autism are similar to what we observe in males and females without autism. Our study showed that compared with males, females (with and without autism) do better in assessments of processing speed, cognitive flexibility, verbal learning and memory and semantic fluency. Our results suggest that although females show different cognitive performance to males, these sex differences were not specific to the group with a diagnosis of autism.