["Family Process, Volume 65, Issue 3, September 2026. ", "\nABSTRACT\nTransgender and nonbinary (TGNB) individuals often face a lack of acceptance within their families, which can have lasting consequences for mental health and well‐being. In this article, we focus on one family model that may be particularly risk‐enhancing in this regard—patriarchal families, characterized by binary thinking, hierarchical assumptions about gender and age, and an obedience‐oriented family order. We examine whether family identity and adverse childhood experiences (ACEs) mediate the relationship between patriarchal family culture and mental health outcomes. A sample of 203 TGNB adults in Poland completed measures of perceived family support for patriarchal culture, family identity, childhood adversity, and mental health indicators (symptoms of depression and generalized anxiety, as well as life satisfaction). Path analysis showed that growing up in families perceived as strongly supportive of patriarchal culture was associated with lower family identity and higher levels of ACEs. Both these factors mediated the effect of patriarchal family culture on depressive symptoms. ACEs alone mediated anxiety, while family identity alone mediated life satisfaction. These findings suggest that patriarchal family culture may relate to mental health largely through the disruption of family identity and early adverse experiences. It underscores the need for interventions, policies, and therapeutic practices that move beyond rigid family models and individual coping, and instead address patriarchal power dynamics by fostering inclusive, safe, and validating relationships for TGNB individuals.\n"]