Feed is critical to the aquaculture industry’s development and long-term success. Feeds might be of plant or animal origin. Fish meal has recently dominated fish feed due to a number of variables, including its high protein content, superior essential amino acid profile, improved nutrient digestibility, absence of antinutritional factors, affordability, and accessibility. However, fish meal, the best protein source for fish feed, is presently under threat, jeopardizing feed formulators’ capacity to rely on it more extensively. Despite their promise, several plants remain underused in the fish feed sector. These plants’ cost effectiveness, availability, and sustainability potential, together with their nutritional content, position them to compete well with currently used plants. Aquatic macrophytes, also known as aquatic plants, are large plants that grow in or near water, including submerged, floating, or emergent species. They are found in both freshwater and marine environments and play vital roles in the aquatic ecosystem. Their use as fish nutrition has gained attention in recent years as a sustainable alternative to traditional fish feed in aquaculture. Utilizing medicinal herbs and plants is a quick, accessible, economical, effective, and environmentally friendly way to support the socioeconomic and sustainable growth of contemporary aquaculture practices. Due to their affordability and environmental friendliness, aquaculture companies have favored phytotherapy-based methods and substances for increasing culturable fishes’ resistance to a range of aquatic diseases. This chapter elaborates on the diverse applications of medicinal herbs/plants and their uses as a nutrition to fulfill the nutrition requirement in aquaculture and a major step toward organic aquaculture.