This meta-analysis synthesizes research on using ingroup role models to improve the performance and interest of underrepresented students in science, technology, engineering, and math (STEM). A systematic literature search resulted in forty-five studies that met the selection criteria, including the presence of a comparison group. Both lab and field studies suffered from small sample bias, with smaller sample sizes predicting larger effect sizes among lab studies, but smaller effect sizes among field studies. Correcting for small sample bias, ingroup role models had a small, but significant positive overall effect (d = 0.20) among field studies and a non-significant overall effect (d = 0.04) among lab studies. The only significant moderator was level of interaction, with in-person role models having smaller effects among lab studies (p = 0.008). Implications for interventions to increase the representation of female and underrepresented minority students in STEM and future directions for research are discussed.