Background: There is no one agreed definition of self-advocacy, but it can be taken to include actions and concepts such as standing up for one's rights and self-determination. Method: A review of studies examining the psychological and social impact of self-advocacy group membership on people with intellectual disabilities was conducted. Systematic searches of electronic databases (PsycINFO, Scopus, Web of Science and ProQuest's Sociology Database), and manual searches of reference lists and citations, identified 12 studies. Results: "Empowerment" and "increased confidence" were frequently reported outcomes. "Belonging," increased opportunities for social connections and changed self-identity were also key themes. Conclusions: Limitations of the review included difficulty categorizing outcomes, and limitations of the evidence base included a lack of quantitative studies. Implications of the review include an observation that the role of self-advocates in the research literature could be extended to the co-construction of research agendas.