Short-chain fatty acids, including butyrate and its derived forms, have been used as dietary supplements to reverse or ameliorate the potential negative effects of plant-derived ingredients in aquaculture diets, and have a multitude of well-demonstrated physiological and health enhancing effects in mammals and livestock. Tributyrin, a butyric acid derivate, has been assessed as a supplement in the diets of farmed animals, with promising results in several species. In fish and crustaceans, the dietary inclusion of tributyrin is more recent and has been less studied but results suggest that it may be highly advantageous for aquatic animals. This is particularly important for carnivorous species, whose diets need to be optimised towards the reduction of the fishmeal content to enhance the environmental and economical sustainability of the sector. The present work characterises tributyrin and presents the main results of its use as a dietary source of butyric acid in feeds for aquatic species. The main focus is given to aquaculture species and how tributyrin, as a feed supplement, can contribute to optimising plant-based aquafeeds.