Nietzsche is one of the most subversive ethical thinkers of the Western canon. This book offers a critical assessment of his ethical thought and its significance for contemporary moral philosophy. It develops a charitable but critical reading of his thought, pushing some claims and arguments as far as seems fruitful while rejecting others. But it also uses Nietzsche in dialogue with, so to contribute to, a range of long-standing issues within normative ethics, metaethics, value theory, practical reason, and moral psychology. The book is divided into three principal parts. Part I examines Nietzsche’s critique of morality, arguing that it raises well-motivated challenges to morality’s normative authority and value: his error theory about morality’s categoricity is in a better position than many contemporary versions; and his critique of moral values has bite even against undemanding moral theories, with significant implications not just for rarefied excellent types but also us. Part II turns to moral psychology, attributing to Nietzsche and defending a sentimentalist explanation of action and motivation. Part III considers his non-moral perfectionism, developing models of value and practical normativity that avoid difficulties facing many contemporary accounts and that may therefore be of wider interest. The discussion concludes by considering Nietzsche’s broader significance: as well as calling into question many of moral philosophy’s deepest assumptions, he challenges our usual views of what ethics itself is—and what it, and we, should be doing.