Essential oils (EOs) are volatile aromatic plant secondary metabolites and can be derived from different plant parts. EOs are renowned for their antimicrobial, antioxidant, and anti-inflammatory properties, making them valuable for diverse applications in healthcare, agriculture, and environmental sustainability. Being natural and effective, EOs exhibit significant efficacy against various pathogenic microorganisms, offering an eco-friendly alternative to synthetic chemicals/antibiotics. However, the long-term use of essential oils is limited by inherent challenges such as volatility, low water solubility, instability under environmental conditions, and rapid degradation. These limitations reduce their bioavailability and efficacy, especially in prolonged or large-scale applications. Nano-biotechnology has now emerged as a transformative approach to encounter such challenges, enhancing stability, bioactivity, and controlled release. Nano-encapsulation techniques, such as liposomes, polymeric nanoparticles, and solid lipid nanoparticles, protect essential oil components from degradation, improve their solubility, and enable sustained release for prolonged action. Additionally, green synthesis of nanoparticles using essential oils as reducing agents not only stabilizes the oils but also provides eco-friendly methods to create multifunctional nanomaterials. Hence, this chapter discusses the properties and uses of essential oils, limitations of their direct application, and the innovative role of nanobiotechnology in maintaining and enhancing their bioavailability. It also explores diverse applications of EO-based nano-formulations, including antimicrobial coatings, wound healing, cancer treatment, and sustainable agriculture. In conclusion, the integration of essential oils with nanobiotechnology enhances its long-term efficacy and environmental sustainability which can be achieved for research and implementation in various industries for long-term ecological balance and green innovation.