Margaret Cavendish, Duchess of Newcastle (b. 1623–d. 1673), published at least six works of natural philosophy under her own name (the number depends on how one counts various second editions she published). Her prolific output also included poems, plays, essays, speeches, stories, science fiction, and letters to fictional correspondents. Despite Cavendish’s own desire for fame, her reputation has suffered at the hands of readers and biographers who dismissed her philosophical writings without giving them any serious consideration. However, interest in Cavendish’s philosophical theories has increased exponentially since the 1980s. Much of the secondary literature published in the 1980s and 1990s aimed to dispel the idea that Cavendish is not worthy of study and to establish both that Cavendish’s writings were informed by her careful readings of the work of her contemporaries, and that Cavendish’s own philosophical thinking consisted of a detailed, internally consistent alternative to the mechanistic natural philosophy embraced by many of those contemporaries. Now, fortunately, scholars do not feel the need to justify their study of Cavendish. Secondary literature published since the early 2000s on Cavendish’s philosophical work starts from the assumptions that studying Cavendish’s works enriches our understanding of the landscape of 17th-century philosophy and that the details of Cavendish’s views are inherently worth analyzing. The secondary literature on Cavendish is now extensive and comes from many disciplines—English literature, philosophy, history, history of science, political science, and cultural studies, among others—and, accordingly, draws on a variety of methodological approaches. For this bibliography, secondary literature has been chosen which is based on close textual analysis and sensitivity to the historical and philosophical contexts in which Cavendish was writing. Works are divided into the following sections: Primary Sources, Modern Editions, Biographies, Overviews, Online Resources, Anthologies, Natural Philosophy, Epistemology, Political Philosophy, Religion and Theology, and Rhetorical Style.