Trichoderma species are widely recognised for their biocontrol potential against plant pathogens. In this study, we aimed to explore the molecular diversity of Trichoderma isolates and evaluate their antagonistic activity against agriculturally important foliar plant pathogens. Phylogenetic analysis revealed a diverse range of Trichoderma species including T. harzianum, T. viride, T. atroviride, and others within the collected isolates. Antagonistic assays were conducted to assess the biocontrol potential of these Trichoderma isolates against foliar plant pathogens. Dual-culture assays and confrontation assays were performed to evaluate the inhibitory effects of Trichoderma isolates on pathogen growth. Additionally, the production of key antifungal metabolites such as chitinases, Glucanases, and proteases by Trichoderma isolates was quantified to understand their mode of action against pathogens. “Our results demonstrate significant variation in antagonistic activity among Trichoderma isolates, with some strains exhibiting strong inhibitory effects on pathogen growth. Molecular analysis revealed correlations between genetic diversity and biocontrol efficacy, highlighting the importance of selecting appropriate Trichoderma strains for effective biocontrol strategies. These findings contribute to our understanding of Trichoderma-mediated biocontrol and provide valuable insights for developing sustainable management practices for foliar plant pathogens in agriculture.