Stigma refers to societally-deemed inferiority associated with a circumstance, behavior, status, or identity. It manifests internally, interpersonally, and structurally. Decades of research indicate that all forms of stigma are associated with heightened risk for mental health problems (e.g., depression, PTSD, suicidality) in stigmatized youth (i.e., children, adolescents, and young adults with one or more stigmatized identities, such as youth of Color and transgender youth). Notably, studies find that stigmatized youth living in places with high structural stigma - defined as laws/policies and norms/attitudes that hurt stigmatized people - have a harder time accessing mental health treatment and are less able to benefit from it. In order to reduce youth mental health inequities, it is imperative for our field to better understand, and ultimately address, stigma at each of these levels. To facilitate this endeavor, we briefly review research on stigma and youth mental health treatment, with an emphasis on structural stigma, and present three future directions for research in this area: (1) directly addressing stigma in treatment, (2) training therapists in culturally responsive care, and (3) structural interventions. We conclude with recommendations for best practices in broader mental health treatment research.