This chapter explores positionality as a central concern in critical self-study research. It advances the argument that deliberate and continuous investigation of a researcher’s identities, social locations, and embodied experiences productively contributes to both the trustworthiness of the inquiry and the likelihood that it can promote equity-oriented outcomes. Drawing upon critical consciousness as a frame of thought, positionality is situated as a dynamic and multifaceted concept. Positionality includes race, culture, gender, socioeconomic status, language, and professional identities. These demarcations of self serve to shape and inform the perspectives, methodological decision-making, and interpretations of data researchers employ. The chapter discusses the notion of diffraction as a conceptual tool to extend beyond traditional approaches for reflexivity. As such, diffraction enables a deeper exploration of a self-study researcher’s ontological positions and how these constitute the phenomena under investigation, most especially professional practice. As such, diffraction further serves to challenge notions of objective knowledge production. The chapter provides a review of selected S-STEP literature, with an emphasis on positionality. These inquiries highlight how teacher educators have productively addressed the complexities of positionality in relation to various identities and professional contexts, illuminating the tensions inherent in being an insider or outsider regarding the aims of the inquiry or professional setting, and how these serve to inform the researcher’s equity focus. The chapter revisits a previous self-study publication by the author and employs a diffractive reexamination to gain further insights into gender and heteronormativity in relation to the author’s positionality. This illustrates how attending to intersectionality can enhance a self-study and serve to promote allyship with others while challenging systemic inequities and deficit-based ideologies. The chapter concludes with prompts and exercises along with suggested readings.