<p>Aquaculture plays a crucial role in boosting global fish production, providing a protein-rich, safe, reliable, and cost-effective food source to meet the nutritional needs of the world’s growing population. The global transition of aquaculture practices from extensive to intensive systems has led to the emergence of novel pathogens and an increased reliance on chemical therapeutics. In response to the adverse effects of the use of synthetic drugs and chemicals, the past decade has witnessed the development of alternative therapeutic strategies. Among these, plant-based extracts have demonstrated significant potential as antimicrobial agents, growth enhancers, and immunostimulants. Fish immunity and general health have been improved by the antiparasitic, antibacterial, and antifungal qualities of medicinal herbs. By reducing reliance on synthetic chemotherapeutics, incorporating herbal supplements into aqua feeds helps mitigate environmental concerns and promote sustainable aquaculture practices. Furthermore, phytotherapy has been shown to enhance disease resistance, improve fish welfare, and enhance growth performance all of which ultimately led to higher production efficiency. Incorporating phytotherapy into aquaculture can enhance the industry’s sustainability and competitiveness in the market, given the growing customer demand for sustainably produced seafood. Organic extracts derived from various medicinal plants and herbs can activate the immune system, inducing downstream immune responses that enhance the fish’s resistance to pathogenic infections. Despite their promise, the application of plant extracts in aquaculture remains in its nascent stage and is primarily limited to experimental trials on laboratory animals. This review explores the historical background, mechanisms of action, and potential future applications of plant-derived extracts in modern aquaculture practices.</p>