Many types of bias and discrimination relevant to our work in STEM education and research training are now recognized, such as racism, sex-based discrimination, and xenophobia, as well as the impact of combinations of dimensions of diversity, such as gender and race (intersectionality). One dimension of diversity where we don't often recognize bias is linguistic diversity, including regional varieties, such as Appalachian or New York urban (dialects), ethnic varieties, such as African-American Vernacular English or Spanish-Influenced English (sociolects), bilingualism, speaking a first language other than English, and using combinations of these. Sometimes called the “last acceptable prejudice,” awareness of language diversity and its powerful impacts is comparatively low, and misunderstandings are common, including in higher education, academia, and STEM research. This workshop will present concepts and vocabulary for exploring language diversity; briefly review the evidence base on effects of language diversity in STEM education; and share strategies for working productively and respectfully with it.