Gender diversity is relatively common in youth, with rates increasing in the general population. This increase may be related to decreased stigma in gender expression, adolescent experimentation, environmental factors or due to the recent interest in quantitatively measuring this trait. Gender diversity in and of itself is a not a psychiatric disorder. But mental health providers might see gender diverse youth if there is the desire for gender-affirming treatment, for assessing and treating of co-occurring psychiatric disorders or to promote resilience in situations where bullying and stigmatisation are taking place. As such, clinicians should be prepared to provide a confidential and competent environment that recognises the vast range of gender diversity currently seen in youth. In addition, while research on mental health in gender diverse youth has substantially expanded in the past decade, limitations of these data influence interpretation and generalisability. Well-designed studies should address gaps, such as long-term follow-up periods for gender diverse youth and those who have received gender affirmative care. They should also examine developmental trajectories and the stability of gender identity. Gender diversity in racial and ethnic minorities who may have different psychiatric presentations should also be addressed in future research.