This introduction argues that physical illness is an important category for literary modernism. Through a close reading of Virginia Woolf’s ‘On Being Ill’ (1926), the author argues that the altered, often intensified forms of embodied experience in illness, constitute an important subject, method, and manner of writing. Self-consciously ‘new’, Woolf’s proposal for a canon of illness writing resembles a voyage of self-discovery, a linguistic experiment, and a phenomenological study. Requiring innovative stylistic effects, physical illness reveals a world at once strange and familiar, in a manner central to modernism’s own distinctiveness. The emphasis on physical illness is clarified with regard to current and historical categorization, as is the relationship between illness, disability, and their attendant terminology. It also explains the predominant focus on textual rather than authorial illness, and on illness rather than medicine.