Biopesticides are the derived products prepared from the living microbes such as plants, animals, fungi, bacteria, viruses, and minerals or their bioproducts that are being widely used against devastating phytopathogens. The use of biopesticides in agricultural fields is a sustainable, economical, and eco-friendly approach compared to the synthetic fungicides because of its target-specificity, biodegradability, and environmental safety property. Among the different biocontrol agents (BCAs) used worldwide, Trichoderma spp. based biofungicides are presently considered as relatively potential and most dominating commercial biofungicide in the global biopesticide market. About 60% of all fungal-based BCAs are contributed by Trichoderma-based biopesticides which are available in different formulations. It is also more popular due to its diverse mechanisms of biocontrol that include antibiosis, colonization, competition, direct mycoparasitism, etc. against a wide range of soil (Sclerotium, Rhizoctonia, Fusarium, Macrophomina, Phytophthora spp.), foliar (Phyllactinia, Colletotrichum, Cladosporium spp.), and post-harvest phytopathogens (Penicillium, Aspergillus, Rhizopus, Botrytis spp.), etc. In this chapter, we have discussed the reasons behind the wide acceptance of Trichoderma sp. as a BCA and its dominance in the global biofungicides market.