Weight bias and stigma are widespread, unjust, and harmful to health. Increased empirical attention to the internalization of weight bias and stigma (or weight self-stigma) has revealed significant health implications that require further study and intervention. This review summarizes current knowledge on the conceptualization, measurement, prevalence, and correlates of internalized weight stigma. Associations with mental and physical health outcomes and evidence from emerging interventions are discussed, along with scientific challenges, knowledge gaps, and opportunities to advance the understanding and reduction of this and other forms of internalized health-related stigma. (PsycInfo Database Record (c) 2024 APA, all rights reserved).