This review discusses natural antioxidants in foods and medicinal plants, focusing on their extraction, assessment, and resources. Natural antioxidants, such as polyphenols and carotenoids, have various biological effects, including anti-inflammatory, anti-aging, and anticancer properties. Effective extraction and assessment of these antioxidants are crucial for their application in functional foods, pharmaceuticals, and food additives. The review covers green extraction technologies, antioxidant activity assessment methods, and main resources from food and medicinal plants. Extraction methods include ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), enzyme-assisted extraction (EAE), pressurized liquid extraction (PLE), and supercritical fluid extraction (SFE). Each method has advantages in terms of extraction efficiency, time, and yield. UAE is effective for extracting anthocyanins and phenolic compounds, while MAE is efficient for polyphenols. EAE is a green method with mild conditions, PLE is suitable for various antioxidants, and SFE is a sustainable method with high extraction efficiency. The review also discusses the assessment of antioxidant activity using methods like TEAC, FRAP, ORAC, and cellular assays. These methods help rank antioxidant plants and recommend best antioxidant foods. The study highlights the importance of selecting appropriate extraction methods based on efficiency, economic feasibility, and environmental impact. Non-conventional methods are preferred for their energy efficiency and reduced solvent use. The review concludes that UAE and MAE are the most feasible and economically profitable methods for large-scale extraction.This review discusses natural antioxidants in foods and medicinal plants, focusing on their extraction, assessment, and resources. Natural antioxidants, such as polyphenols and carotenoids, have various biological effects, including anti-inflammatory, anti-aging, and anticancer properties. Effective extraction and assessment of these antioxidants are crucial for their application in functional foods, pharmaceuticals, and food additives. The review covers green extraction technologies, antioxidant activity assessment methods, and main resources from food and medicinal plants. Extraction methods include ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), enzyme-assisted extraction (EAE), pressurized liquid extraction (PLE), and supercritical fluid extraction (SFE). Each method has advantages in terms of extraction efficiency, time, and yield. UAE is effective for extracting anthocyanins and phenolic compounds, while MAE is efficient for polyphenols. EAE is a green method with mild conditions, PLE is suitable for various antioxidants, and SFE is a sustainable method with high extraction efficiency. The review also discusses the assessment of antioxidant activity using methods like TEAC, FRAP, ORAC, and cellular assays. These methods help rank antioxidant plants and recommend best antioxidant foods. The study highlights the importance of selecting appropriate extraction methods based on efficiency, economic feasibility, and environmental impact. Non-conventional methods are preferred for their energy efficiency and reduced solvent use. The review concludes that UAE and MAE are the most feasible and economically profitable methods for large-scale extraction.