Resveratrol (RES) is a type of polyphenolic defense compound that is widely found in many plants, such as grapes, knotgrasses, and blueberries. RES has been used as a new green feed additive in the aquatic industry due to its biological activities, such as anti-oxidation, anti-inflammation, anti-bacteria, and immune regulation. The physicochemical properties, bioavailability, biological activities, and regulatory mechanism of RES are summarized in this article, and the application of RES in aquatic production is also summarized. The results showed that appropriate concentrations of RES were beneficial to the production performance, immune health, and fat metabolism regulation in aquatic animals. In addition, RES could effectively prevent bacterial pathogens from infecting aquatic animals. However, the mechanism underlying its biological activities is still not fully understood, and there is a lack of basic research on the appropriate dose for different aquatic animals. In-depth research should be carried out as soon as possible in order to provide reference for further promoting the application of RES to aquatic animals.