Fish represent approximately half of all vertebrate species, yet have received little attention as models for aging research relative to invertebrate organisms or rodents. However, the basic gerontological characteristics of several fish species have been studied and provide compelling data for further investigation. In particular, guppies have proved to be an invaluable model for evolutionary analyses of aging, killifish are short-lived and may be exploitable for life span manipulation studies, and zebrafish come with a formidable armament of associated biological tools from their widespread use as a model of vertebrate development. These fish are well suited for the investigation of basic processes implicated in aging, such as insulin signaling, oxidative stress, and comparative studies of species with widely divergent longevities. Under-explored areas for which these fish may also provide unique research opportunities include their use as platforms for disease modeling, drug discovery, and regenerative medicine.