Assessment for social justice seeks to explore the ways in which our assessment practices reflect and nurture broader principles of social justice. In this chapter, I explore the specific aspects of epistemic justice that we should consider when reflecting on our assessment practices and assumptions in more detail. Assessment for social justice and epistemic justice are also closely linked to the need for a radical rethinking of what is meant by the now common term ‘authentic assessment’. This chapter employs three epistemic scholars to demonstrate the ways in which this essential epistemic aspect can be brought into discussion with new understandings of authentic assessment. To this end, I discuss the decolonial work of Santos to help orientate assessment into a broader social context. Using Bernstein’s work on knowledge in higher education, I then consider the ways in which assessment should be attuned to the knowledge it seeks to evaluate. Finally, through Fricker’s work on epistemic justice, I explore how this can provide an initial foundation for genuinely transformative assessment change by helping us to understand how injustice occurs.