Rationality has long been a central topic in philosophy, crossing standard divisions and categories. It continues to attract much attention in published research and teaching by philosophers as well as scholars in other disciplines, including economics, psychology, and law. The Oxford Handbook of Rationality is an indispensable reference to the current state of play in this vital and interdisciplinary area of study. Twenty-two newly commissioned chapters by a roster of distinguished philosophers provide an overview of the prominent views on rationality, with each author also developing a unique and distinctive argument.