The increasing worldwide demand for plant-based sustainable pest control methods has prompted the exploration of alternative approaches, such as the use of plant essential oils (EOs) to combat insect pests of food grains. EOs has immense potential to be developed as plant-based alternative insecticides to hazardous chemical insecticides as supported by a plethora of literature. However, their uses in large-scale application are limited due to their short life span, little solubility in water, and quick vaporization. To overcome these limitations, nanoencapsulated essential oils (NEOs), which are EOs encapsulated within nanoparticles, offer enhanced stability, controlled release, and improved bioactivity as proved in many modern research publications. The present chapter aims to explore the efficacy of EOs and prospects of NEOs against various important insect pests of food grains in different ways. By offering a novel solution to insect pest control, NEOs present an innovative tool for the safety of stored food grains, contributing to food security and for overcoming the challenges faced while using pure EO as insecticide. Furthermore, future research studies focusing on the use of NEOs as insecticides should be done in details in the real food system and their safety profile, an area that needs more research input.