Abstract
Graduate and undergraduate teaching assistants (TAs) have become increasingly responsible for facilitating coursework in the science, technology, engineering, and mathematics (STEM) disciplines. Yet, they often receive limited, if any, professional development (PD) to support them in this endeavor and to accelerate their growth as educators. This themed issue on STEM TA PD reflects a concerted effort to address this concern, with the articles comprising the issue representing a wide array of topical contributions by authors with a diversity of roles across institutions/organizations.