Family members frequently report experiencing social stigma due to their relationship to a loved one with mental illness. Adults’ perceptions of this family stigma have been linked to elevated feelings of distress and a lower quality of life. The present study examined the mediating roles of maternal responsibility and maternal regard in the relationship between perceived family stigma and psychological well-being among young adult children of mothers coping with mood disorders. A sample of 172 young adult children of mothers diagnosed with a mood disorder (123 women, 49 men; M = 23 years old; SD = 1.8) completed an online survey to assess feelings of maternal responsibility and regard, family stigma, and psychological well-being. Correlational results suggest that higher scores on maternal responsibility were generally associated with higher levels of family stigma. Maternal regard scores were generally associated with lower levels of family stigma and higher levels of psychological well-being. Young adults’ feelings of responsibility and regard in their relationship with their mother served a mediating role in relation to their reports of family stigma and psychological well-being. Mediation findings suggest that young adults’ reports of higher levels of maternal responsibility contributed to a greater sense of well-being in response to higher levels of family stigma. Additionally, young adults’ reduced feelings of maternal regard generally contributed to lower levels of well-being in response to higher levels of family stigma. Implications of findings for family research on social stigma and interventions for adult children of mothers with mood disorders are discussed.