Objective: Trans and gender diverse young people experience mental health difficulties self-harm and suicidality at markedly higher rates than the general population, yet they often feel isolated from mental health services. There is little qualitative research on the experiences of trans and gender diverse young people accessing mental health support in Australia. The objective of this study was to comprehensively explore the experiences of trans and gender diverse young people in Australia who have sought mental health support from therapists, counsellors, psychiatrists and/or inpatient care providers. Methods: We report on findings from the Trans Pathways study, which was a mixed-methods study to evaluate the experiences of trans and gender diverse young people accessing mental health services: specifically, therapy and counselling services, psychiatric services and mental health inpatient services. Results: A total of 859 trans and gender diverse young people aged 14–25 years across Australia completed an anonymous online questionnaire. Therapy and/or counselling services (64.4%) were most frequently sought by trans and gender diverse young people in this study, followed by psychiatric services (43.0%) and mental health inpatient services (12.3%). The findings demonstrated that many mental health professionals lacked expertise in gender diversity, and that trans and gender diverse young people found it difficult to locate mental health professionals who were able to meet their needs in a timely manner. Conclusion: These findings indicate that training is necessary for all mental health professionals to improve their knowledge of gender diversity, enhance the support provided to trans and gender diverse young people and help to address the high rates of poor mental health. The findings outlined here provide insight into the areas in which clinicians could optimise their care of trans and gender diverse young people.