Discrimination toward individuals with lived experiences of mental illness is widespread within the field of clinical psychology. Further, there is some presence of clinical psychologists who are both consumers and providers of mental health services, termed prosumers. However, no research has evaluated how witnessing discrimination as part of professional activities may influence prosumers' experiences with internalized stigma, anticipated stigma, and stigma resistance. This exploratory study aimed to establish associations and interactions between having witnessed discrimination toward others with lived experiences of mental illness and internalized stigma, anticipated stigma, and stigma resistance from the perspective of prosumers within the clinical psychology field. A cross-sectional quantitative approach was employed to understand these dynamics by utilizing descriptive, correlational, and multivariate regressions analysis. A total 175 prosumers (39 graduated doctoral-level clinical psychologists and 136 in training) completed survey measures pertaining to witnessed discrimination, internalized and anticipated stigma, and stigma resistance. Prosumers reported witnessing frequent subtle and overt discrimination by their colleagues, supervisors, and faculty members. Overt discrimination was reported as witnessed more frequently compared with subtle discrimination experiences or microaggressions. Our findings have implications for the prevalence of witnessed discrimination and how these may create cumulative experiences of stigma and stigma resistance among prosumers in clinical psychology. Further research should explore additional understanding of how clinical psychologists, including prosumers, may hold stigmatizing attitudes and perpetuate discrimination toward individuals with lived experiences of mental illness. (PsycInfo Database Record (c) 2024 APA, all rights reserved).