BackgroundAutism spectrum traits are increasingly being reported in individuals who identify as transgender, and the presence of such traits have implications for clinical support. To-date little is known about autism traits in individuals who identify as nonbinary. AimsTo empirically contribute to current research by examining autistic traits in a self-identifying transgender and nonbinary gender group. MethodOne hundred and seventy-seven participants responded to a survey consisting of the Autism Spectrum Quotient (AQ), the Empathy Quotient (EQ), the Systematising Quotient (SQ) and the Reading the Mind in the Eyes Task (RME). Comparisons were made between cisgender, transgender and nonbinary groups. ResultsIndividuals with autism spectrum disorder (ASD) or meeting the AQ cut-off score for ASD were over-represented in both the transgender and nonbinary groups. The key variables differentiating the transgender and nonbinary groups from the cisgender group were systematising and empathy. Levels of autistic traits and cases of ASD were higher in individuals assigned female at birth than those assigned male at birth. ConclusionsA proportion of individuals seeking help and advice about gender identity will also present autistic traits and in some cases undiagnosed autism. Lower levels of empathy, diminished theory of mind ability and literalness may impede the delivery of effective support. Clinicians treating transgender and nonbinary individuals, should also consider whether clients, especially those assigned female at birth, have an undiagnosed ASD.