Epistemic injustices are the distinctly epistemic harms and wrongs which undermine or depreciate our capacities knowers. This dissertation develops a theory of epistemic injustice and justice which accounts for excesses in epistemic goods as a source of epistemic injustice. This is a theory of epistemic overload as epistemic injustice. The dissertation can be divided into three parts: 1) motivational, 2) theoretical, 3) applications and implications. First, Chapters 1 and 2 motivate the study of epistemic injustice and epistemic overload. Chapter 1 identifies a gap in the literature on epistemic injustice concerning excesses in epistemic goods as sources of epistemic injustice while canvassing the major themes and debates of the field. Chapter 2 levels an objection to ‘proper’ epistemology, thereby providing an indirect defense of the study of epistemic injustice. Second, theoretical development occurs in are Chapters 3, 4, 5, 6. Chapter 3 initiates the argument for epistemic overload, while Chapter 4 extends the case for epistemic overload, identifying several epistemic injustices arising from excesses of understanding, credibility, and truth. Chapter 5 explains the oversights of prior theorists by developing a more descriptively adequate account of social epistemics that explains the many sites of epistemic injustice. Chapter 6 develops a two-stage contractualist theory of epistemic in/justice to explain the bad-making features of epistemic injustices and generates the duty of epistemic charity. The third part of the dissertation applies the findings of earlier chapters to contemporary practical and theoretical problems. Chapter 7 employs the contractualist reasoning of Chapter 6 to address and ameliorate problems from excesses in the uptake and circulation of hermeneutical resources and true-beliefs. Chapter 8 considers the mutual dependence relations between political phenomena and epistemic in/justice, showing that accounts of political justice depend upon or presuppose epistemic justice. Finally, Chapter 9 applies epistemic overload to the use of big data technologies in the context of predive policing algorithms. An abductive argument concludes that the introduction of the “Strategic Subjects List” as part of a Chicago policing initiative in 2013 introduced understandings which likely contributed to gun-violence in Chicago and which constitutes an epistemic overload. In sum, the dissertation shows the theoretical and practical significance of epistemic overload as epistemic injustice. / Ph. D.