The aquaculture industry faces significant challenges due to infectious diseases that can devastate fish populations and impact economic viability. Probiotics have emerged as a promising strategy for disease control, offering a sustainable alternative to traditional antibiotics. This review focuses on six key bacterial strains: Aeromonas hydrophila, Yersinia ruckeri, Lactococcus garviae, Streptococcus agalactiae, Streptococcus dysgalactiae, and Streptococcus iniae, which are known to cause severe infections in aquatic species. Probiotics, defined as live microorganisms that confer health benefits to the host, can enhance the immune response of fish, improve gut health, and outcompete pathogenic bacteria. The mechanisms of action include the production of antimicrobial substances, competition for nutrients and adhesion sites, and modulation of the host's immune system. This literature review synthesizes current research findings on the efficacy of these probiotics against the aforementioned pathogens, highlighting their potential to reduce disease incidence and promote healthier aquaculture practices. The integration of probiotics into aquaculture not only addresses the pressing issue of antibiotic resistance but also supports the overall sustainability of the industry. Future research directions are proposed to further elucidate the mechanisms of action, optimize probiotic formulations, and evaluate their long-term effects on fish health, and aquaculture productivity.