Various biotic stresses in agroecosystems dramatically impact sustainable agriculture, influencing both the quantity and quality of global crop production. An adequate eco-friendly approach to mitigate the negative effects of biotic stress is indispensable. Trichoderma species promote and enhance plant growth through various specialized mechanisms, such as biologically controlling soil-borne diseases by producing and activating enzymes, generating antibiotics, and invading phytopathogenic fungi. Additionally, as the most prevalent saprophytic fungi in the rhizosphere, Trichoderma acts as a mycoparasite, aiding plants in coping with biotic stresses. This chapter discusses the genetics, mechanisms, and uses of Trichoderma species, with particular emphasis on mycoparasitism, antibiosis, and the biosynthesis of volatile organic compounds and secondary metabolites. This study also details the manner in which Trichoderma is induced through systemic resistance by signaling pathways that involve ethylene, salicylic acid, and jasmonic acid. Moreover, the impact on plant growth and yield is also evaluated with respect to the interaction between the soil microbial population, the host plant, and Trichoderma. In this chapter, the potential of Trichoderma species in sustainable agriculture is explored, together with the challenges related to their use, including taxonomy, biological properties, and practical application.