Outbreaks of Aeromonas hydrophila cause major losses in African catfish (Clarias gariepinus) farming, while antibiotic raises resistance concerns. This study evaluated bacteriophages from a diseased catfish pond as local biocontrol agents. In vitro, phages reduced bacterial density by over 50% within 24 h (P<0.05). In vivo, phage treatment significantly improved survival compared with infected controls (P<0.05) and moderated hematological disruption. After infection, clinical signs were milder in phage-treated fish than in non-treated control. These results indicate that locally sourced phages can mitigate A. hydrophila infection and support future disease management in C. gariepinus aquaculture. © 2026, Central Fisheries Research Institute. All rights reserved.