Seaweeds have gained significant attention in agriculture due to their diverse applications, particularly as a source of bioactive compounds with antimicrobial properties. Green, brown, and red algae are known to contain substances that exhibit antibacterial activity and inhibit the growth of pathogenic microbes. This study aimed to evaluate the efficacy of different seaweed extracts in suppressing Xanthomonas oryzae pv. oryzae, a major pathogen in rice. Among the tested extracts, Sargassum wightii at 20% concentration demonstrated the highest antibacterial activity, reducing bacterial colony formation to 1.8 x 10⁵ CFU/mL. These findings suggest that seaweed extracts, particularly Sargassum wightii, could serve as a natural and effective alternative for managing bacterial diseases in crops.