Supercritical fluid-assisted extraction (SCFE) is a cutting-edge and eco-friendly technology for efficiently extracting essential oils and bioactive compounds from food byproducts. Unlike conventional solvent-based extraction methods, SCFE offers superior selectivity, higher yield, and minimal environmental impact, making it a promising approach for sustainable processing and food waste valorization. SCFE offers minimal thermal degradation and the elimination of toxic solvents, with carbon dioxide (CO₂) as the most widely used supercritical fluid due to its low critical temperature, nontoxicity, and cost-effectiveness. This protocol provides a comprehensive overview of SCFE, emphasizing theoretical principles, materials, methods, and key parameters influencing efficiency. The Materials section details the preparation of food byproducts, such as citrus peels and spice waste, highlighting optimal drying, grinding, and pretreatment techniques to enhance interaction between CO₂ and target compounds. The Methods section outlines SCFE steps, including achieving supercritical conditions, solute dissolution, and separation, with emphasis on parameter optimization of pressure, temperature, CO₂ flow rate, and extraction duration to maximize yields. The Notes section addresses operational challenges, sustainability, and scalability, providing practical insights for industrial implementation. By detailing these aspects, this protocol supports the adoption of SCFE as a green technology for producing high-value natural ingredients, contributing to eco-friendly processing, and advancing circular economy objectives.