Fish are the largest class of vertebrates, with over 25,000 estimated species and subspecies. Fish have evolved unique anatomical and physiological adaptations, when compared to terrestrial vertebrates, for life in a range of aquatic environments. Interest in aquatic animal health has been recorded in Eastern and Western cultures for more than 2,000 years. In recent times, there has been an increase in the numbers of aquatic animals being used as companion animals or pets, for food and in laboratories, as well as in restoration and conservation programmes. There has also been a corresponding increase in concern for their health and welfare. Moral and ethical considerations require the optimisation of husbandry practices and advances in aquatic animal health for these animals. As with other vertebrates, veterinarians are best equipped to meet the challenges for aquatic animal health from clinical, scientific and legal perspectives. To accomplish this goal, veterinary education must incorporate aquatic animal health throughout graduate curricula, create advanced postgraduate training opportunities, and support a continuum of professional development opportunities for all levels of aquatic animal health expertise.