 This entry starts with a historical background of Bradley’s regress arguments. Section 1 opens with an outline of some of the historical precursors of Bradley’s regress arguments in ancient, medieval, and modern philosophy. It then presents in some detail the regress arguments as they were formulated by Bradley in Appearance and Reality (1893), as well as Bradley’s later concerns with complexes and relations. Section 2 discusses the two types of extensions that Bradley’s regress arguments have undergone—with respect to the ontology that they apply to, and with respect to the exact sort of problem in view. Section 3 presents six common types of replies that can be found in the literature surrounding Bradleyean problems. And Section 4 concludes by describing some of the recent applications of the regress arguments in the literature on grounding, composition of objects, and unity of the proposition.