This chapter contributes to the establishment of radical psychological practice by exploring its epistemology—the study of how knowledge within a discipline is gathered and defined (Falmagne, 2014). The logic of the chapter is rooted in Michel Foucault’s theories on discourse as a mechanism by which power can be asserted via knowledge that constitutes “truths” regarding the world. This, in turn, perpetuates power as this knowledge is incorporated and promulgated by professions like psychology. The foundational assumptions within psychological paradigms, therefore, can be analyzed to reveal the imprint of status quo agendas. These agendas are subsequently manifested in theory, research, and ultimately, psychological practices that operate to the benefit of social dominants and to the detriment of marginalized groups. As such, there is an inextricable link between epistemology, research, and practice. If innovative radical psychological practices are to align with the dismantling of systems of oppression, those practices must emerge from an understanding of how all these structures emerge from a common epistemology.