The functional theory of boredom maintains that boredom ought to be defined in terms of its role in our mental and behavioral economy. Although the functional theory has recently received considerable attention, presentations of this theory have not specified with sufficient precision either its commitments or its consequences for the ontology of boredom. This essay offers an in-depth examination of the functional theory. It explains what boredom is according to the functional view; it shows how the functional theory can account for the known characteristics of boredom; and it articulates the theory’s basic commitments, virtues, and limitations. Ultimately, by furthering our understanding of the functional theory of boredom, the essay contributes to a better theoretical grounding of boredom.