Hinge epistemology was originally developed as an account of perceptual justification and as a response to Cartesian and Humean skepticism. Annalisa Coliva offers the first systematic extension of hinge epistemology into the domains of social and applied epistemology. She advances a novel hinge-theoretic framework that distinguishes between de jure and de facto hinges, a distinction that allows for a nuanced analysis of a broad range of epistemological and social issues. She applies this framework to central debates on common knowledge, genealogical challenges, deep disagreement, and the nature of testimonial justification and trust, including pressing questions surrounding trust in artificial intelligence. Social and Applied Hinge Epistemology further engages with debates on testimonial and hermeneutical injustice, as well as conceptual engineering, with particular focus on the contested and socially significant concept "woman." Beyond these social applications, the book explores the implications of hinge epistemology for understanding psychiatric delusions and the epistemic structure of conspiracy theories, shedding light on how basic commitments shape, constrain, and sometimes distort our cognitive and social lives. By extending hinge epistemology into these diverse contexts, the book demonstrates its power as a unifying framework for addressing both traditional epistemological concerns and contemporary challenges at the intersection of knowledge, society, and practice.