ABSTRACT Aquaculture is a key sector for global food security, but its sustainability and productivity remain constantly questioned. Using 2–8 carbon chain carboxylates (2–8 CCs) has proven to be a promising and beneficial strategy for various fields, including aquaculture. Within the 2–8 CCs, short‐chain fatty acids (SCFAs) have received significantly more attention from researchers than the relatively less‐explored medium‐chain fatty acids (MCFAs). Applying these compounds in aquaculture has improved growth performance, feed efficiency, immune responses, intestinal health, antioxidant capacity, and water quality, thus promoting aquaculture organisms' productivity and sustainability. Furthermore, 2–8 CCs offer significant environmental benefits by reducing the reliance on antibiotics and promoting a healthier gut microbiota, thereby mitigating some ecological impacts of aquaculture. They also contribute to improved waste management practices and developing a more circular economy within aquaculture systems. This review comprehensively examines the current understanding of 2–8 CCs' effects in aquaculture, discussing their roles, environmental impacts, benefits, challenges, and future research directions. The findings underscore the potential of 2–8 CCs to significantly enhance the sustainability and productivity of aquaculture systems, offering a hopeful outlook for the future of the field.