Insect pests pose a significant threat to agriculture, forestry, and public health, causing substantial economic and ecological losses. Traditional pest control methods often rely heavily on chemical pesticides, which may have some adverse environmental and health consequences. As a result, there is a growing need to develop sustainable and environmentally friendly approaches for managing insect pests. Entomopathogens is a diverse group of organisms, which can naturally infect and are pathogenic to insect pest. Several types occur naturally, including bacteria, fungi, viruses, and nematodes, which have coevolved with insect hosts, leading to highly specialized pathogenic interactions. It can be harnessed as biopesticides to target specific insect pests, reducing the need for broad-spectrum chemical pesticides and is ecologically sustainable. Their modes of action range from direct infection and pathogenesis to the production of toxins, ensuring targeted pest control while minimizing nontarget effects. This chapter explores the critical role of entomopathogens in achieving sustainable pest control. Insect pests pose significant challenges to agriculture and the environment, prompting the continuous search for sustainable and eco-friendly pest management strategies. Microbial innovations have emerged as a promising approach to address these challenges. The present chapter explores the role of various microorganisms, including bacteria, fungi, viruses, and nematodes, in sustainable insect pest management. Further, it also provides an overview of the mechanisms underlying the microbial control of insect pests and highlights recent innovations and advancements in the field.