LAUSR

Simple Summary As global aquaculture expands, the need for safe, sustainable alternatives to antibiotics has become increasingly urgent to safeguard the health and productivity of aquatic animals. Caffeic acid (CA), a naturally occurring plant polyphenol, has emerged as a promising candidate owing to its multifunctional bioactivity. This review provides a comprehensive evaluation of CA’s potential applications in aquaculture, synthesizing evidence that CA enhances immune responses, reduces inflammation, exerts antimicrobial effects, and improves overall fish health. Although the research base is still developing, CA appears to act through distinct biological mechanisms that may differentiate it from other plant-derived feed additives. This review also highlights key knowledge gaps, including the need to define optimal dosing strategies, understand species-specific responses, investigate impacts on the gut microbiota, and assess cost-effectiveness for commercial-scale use. Addressing these priorities will lay the groundwork for future studies and support the development of sustainable functional-feed strategies that diminish antibiotic reliance in aquaculture.