Entomopathogenic nematodes (EPNs) belonging to the families Steinernematidae and Heterorhabditidae have emerged as promising biological control agents due to their ability to target a wide range of insect pests in agricultural, horticultural, and forestry systems. Their unique symbiotic association with Xenorhabdus and Photorhabdus bacteria enables rapid insect mortality through septicemia, toxin production, and suppression of host immunity. Over the past three decades, extensive research has advanced the understanding of their biology, ecology, and host– pathogen interactions, leading to the development of efficient in vivo and in vitro mass production systems. Modern formulation technologies such as alginate capsules, gels, nanoemulsions, and oil- based carriers have improved shelf life, stress tolerance, and field applicability. Application innovations, including soil drenches, foliar sprays, seed coatings, root dips, and mechanized or drone-based delivery, have expanded their use against pests such as cutworms, white grubs, armyworms, and borers, while case studies worldwide have demonstrated successful integration into integrated pest management (IPM) programs. Synergistic interactions with entomopathogenic fungi, Bacillus thuringiensis, parasitoids, predators, and botanicals further enhance their efficacy while reducing reliance on synthetic pesticides. Molecular tools, including phylogenetics, genomics, transcriptomics, and proteomics, have provided insights into virulence and adaptation, while CRISPR-based genome editing and biotechnology approaches show potential for engineering climate-resilient strains with enhanced infectivity and persistence. Despite these advances, challenges such as inconsistent large-scale field efficacy, high production costs, limited farmer awareness, and logistical constraints in storage and transport hinder widespread adoption. Regulatory frameworks, biosafety protocols, and extension services play a crucial role in ensuring safe and sustainable use. Looking ahead, the development of climate-resilient strains, precision agriculture integration, nano-formulations, and global commercialization initiatives will strengthen the role of EPNs as core components of sustainable pest management, contributing to reduced pesticide dependency, environmental safety, and long-term agricultural productivity.