This article provides a philosophical overview of some of the central Buddhist positions and arguments regarding animal welfare. It introduces the Buddha's teaching of ahiṃsā or nonviolence and rationally reconstructs five arguments from the context of early Indian Buddhism that aim to justify its extension to animals. These arguments appeal to the capacity and desire not to suffer, the virtue of compassion, as well as Buddhist views on the nature of self, karma, and reincarnation. This article also considers how versions of these arguments have been applied to address a practical issue in Buddhist ethics; whether Buddhists should be vegetarian.