Fittingness explores the nature, roles, and applications of the notion of fittingness in contemporary normative and metanormative philosophy. The fittingness relation is the relation in which a response stands to a feature of the world when that feature merits, or is worthy of, that response. In the late nineteenth to mid-twentieth century, this notion of fittingness played a prominent role in the theories of the period's most influential ethical theorists, and in recent years it has regained prominence, promising to enrich the theoretical resources of contemporary theorists working in the philosophy of normativity. This volume is the first central discussion of the notion of fit to date. It is composed of seventeen new essays covering a range of topics including the nature and epistemology of fittingness, the relation between fittingness and reasons, the normativity of fittingness, fittingness and value theory, and the role of fittingness in theorizing about responsibility. In addition to making important contributions to the debates in the philosophy of normativity with which they're concerned, the essays in the volume support the hypothesis that the notion of fittingness has great theoretical utility in investigating a range of normative matters, across a variety of domains.