Looking at a variety of cases from the early modern period—from debates around astrology to the essays of Michel de Montaigne to the poetry and prose of John Donne and the philosophical fictions of Margaret Cavendish—this essay explores the encounter with materialist thought as an experience of catastrophe. Against the explicit aims of materialist philosophers like Epicurus to encourage peace of mind, early modern authors discovered in materialism a style of thought that felt at once enticing and alarming, even disastrous. “Catastrophic materialism” helps us understand how a much-maligned philosophy captured the imagination, as well as the critical function it served.