Most research on emotions in STEM education has so far been grounded in psychological theories of emotion, studying emotions as individual phenomena. During the past decade, however, STEM education researchers have increasingly been inspiredby social science research that also explores the social and interpersonal nature of emotions. In this contribution, we present an analytic framework for studying emotions in STEM education through the lens of positioning theory, a form of discourse analysis concerned with how people negotiate positions (in terms of rights and duties to docertain things but not others) in social interaction. More specifically, our framework focuses on emotional positioning, which includes (a) use of emotional expressions as discursive resources for positioning, and/or (b) someone being positioned as (un)emotional in certain ways. The framework allows STEM researchers to deepen their understanding of the roles that emotions can play in social interaction (which is particularly relevant for research employing sociocultural perspectives) and the negotiation of power structures in STEM education (which is particularly important inresearch employing critical perspectives). Finally, we demonstrate how emotional positioning analysis also can account for material aspects of emotions and learning.We conclude that materiality can play a significant role in the social construction of emotions, and that both emotions and materiality in STEM can be studied through thelens of emotional positioning.