The study of individual differences in animals and humans has flourished in recent years. This work has revealed personality traits in a wide range of species, including dolphins. However, there are few systematic studies of dolphin personality despite many reasons to assume that personality plays an important role in dolphin behavior. Dolphins live in complex societies and demonstrate a broad and diverse behavioral repertoire, which allows for the possibility of consistent individual differences. In this paper, we discuss the available evidence for individual differences and personality in dolphins from a variety of behavioral contexts from both captive and wild populations, as well as the significance of such differences for theories of dolphin behavior, dolphin welfare, and conservation.