The rising crisis of antimicrobial resistance (AMR) in global aquaculture threatens food security and public health, calling for a shift away from prophylactic antibiotic use. Probiotics offer a potentially viable and sustainable alternative through competitive exclusion, pathogen suppression, and immunomodulation, thereby helping to reduce disease burden. This review integrates current evidence on the application of probiotics to mitigate AMR within a One Health framework, examining their use across feed-based, water-based, and larval-rearing systems. Across diverse species and production contexts, probiotics may help decouple aquaculture intensification from reliance on antibiotics. However, widespread adoption is hindered by strain-specific efficacy, variable performance across environmental conditions, and logistical challenges associated with maintaining and delivering viable organisms. The field also suffers from a paucity of standardized, long-term, multisite trials, which creates uncertainty about efficacy, durability, and safety under commercial conditions. To address these gaps, emerging innovations such as fermentation-based delivery approaches, synbiotics, postbiotics, and microbiome engineering show promise for enhancing probiotic stability and shaping favorable microbial communities. Probiotics should therefore be viewed as an important component of holistic health management, with the potential to influence resistome dynamics while complementing vaccination and biosecurity measures. Realizing these benefits requires transparent reporting, rigorous ecological monitoring, harmonized regulatory standards, and targeted capacity building, particularly in low- and middle-income countries, to promote equitable access.