Gender minority stress refers to social stressors such as discrimination and stigma that gender minorities are subject to. This study examines the relationship between gender minority stress and psychological well-being in trans and gender diverse young people (TGDYP). We used a cross-sectional design to investigate the relationship between gender minority stress and mental well-being in TGDYP aged 16–25. We measured anxiety, depression, general psychological well-being, gender dysphoria, gender minority stress (distal and proximal), resilience and heteronormative beliefs in cisgender (n = 135) and trans and gender diverse (TGD) (n = 106) participants. Hierarchical regression was used to analyse the data. TGD participants had significantly higher levels of anxiety and depression, and poorer general well-being, than cisgender participants. Although the direction of the relationship cannot be determined through our analysis, TGD participants who experienced more minority stress and were assigned female at birth had higher levels of depression and anxiety. TGD participants with higher resilience scores and were assigned male at birth had better well-being overall. Our findings suggest that we should pay attention to minority stress when thinking about how to reduce anxiety and depression in TGDYP. The responsibility for improving well-being lies not just with services but instead should be held by our whole society.