Women and members of many ethnic minority groups continue to be significantly underrepresented in science, technology, engineering, and mathematics (STEM) education and work settings. In this article, we propose that Gloria Anzaldúa's concepts of "nepantla" and "nepantleras/os" can be used to enrich perspectives on underrepresentation among those studying, working, and persisting in STEM fields. We describe how diversity practices may fail to address and foster inclusion in STEM education and workplaces and link inclusion and belonging to engagement and retention in STEM. Recommendations are offered for combining top-down and bottom-up strategies providing information, awareness, and skills training in STEM environments, including recognizing and engaging the insights and experiences of nepantleras/os.