This dissertation develops a Thomistic ethics of honor in light of contemporary concerns that giving honor according to an objective standard of excellence is a dangerous action opposed to authentic personal flourishing, which insufficiently distributes the good of recognition, and which sustains social hierarchies of domination. The central claim advanced over five chapters is that a Thomistic understanding of honor, excellence, and justice supports an ethics of honor in which true honor given in accord with a true objective standard is ordered to personal and communal flourishing, sustains just social order, and is due in various degrees to all people. According to this Thomistic understanding, honor is reverence exhibited in testimony to someone's excellence, a testimony which seeks to confirm belief in that person's excellence in order to burnish his reputation, to increase his glory of a good conscience, to provoke him to greater excellence, to foster friendship, to unite a community in common life, and to perfect the affections of all towards the honored. A true objective standard of excellence is distinguished from false standards both by a consideration of Thomas's metaphysics of goodness, which provides principles to adjudicate the excellence of creatures and their actions as participating in divine goodness both as good in themselves and as possessing the dignity of moving others to goodness, and by a consideration of Thomas's doctrine of love, which show that true honorable goodness is ordered to friendship as enabling the conjunction of cooperation by which friends are united and give joy to each other. Honor is due in justice as a debt of friendship and gratitude, according to an exigency of the ultimate end of beatific convivere with God and the blessed, and since all who bear the image of God represent God, are potential members of Christ by invisible grace, and hold a common office of causing good in others, every human person is owed a debt of honor and reverence.