Executive functions are related to key outcomes. Studies of autistic youth self-report of other nonsocial traits indicate that their insights into their own functioning and internal experiences provide important information that is not captured by their parents' report, but youth self-report of executive function has not been researched in autism. We investigate self- and parent-report on the Behavior Rating Inventory of Executive Function-2 in 197 autistic youth without intellectual disability, including the magnitude and profile of problems reported across subdomains of executive function. We also compare autistic self-report to that of 114 youth with attention deficit hyperactivity disorder and 197 neurotypical youth. We find that autistic youth report significant executive function challenges in comparison to neurotypical youth and a distinctive profile of challenges in comparison to attention deficit hyperactivity disorder youth. Parents and their autistic children diverge regarding the severity of the youth's executive function difficulties, but both emphasize flexibility problems within their profile of executive function challenges. Intraclass correlation coefficients between parent and youth ratings were moderate to poor in the autistic group, indicating that autistic youth report adds important information beyond that captured by their parents' report. These data elevate the importance of asking autistic youth directly about their own executive function.