Endophytes are the microorganisms intricately associated with the plant tissues without causing disease and accelerate the plant growth and development by playing a pivotal role in enhancing plant resilience. Among their many functions, entomopathogenic endophytes have emerged as promising allies in sustainable pest management, producing metabolites and enzymes that deter or kill insect herbivores. They also contribute to plant growth by facilitating nutrient uptake, regulating hormones, and improving stress tolerance. This review highlights the dual role of fungal and bacterial endophytes as growth promoters and natural biocontrol agents, with special emphasis on their mechanisms of action and potential to reduce reliance on chemical pesticides. The future application of endophytes in agriculture, biotechnology, and pharmaceuticals presents new opportunities for environmentally friendly crop protection and improved productivity.