Avocado (Persea americana), originally from Mesoamerica, has emerged as a focus of intense scientific and industrial interest due to its unique combination of nutritional richness, bioactive potential, and technological versatility. Its pulp, widely consumed across the globe, is notably abundant in monounsaturated fatty acids, especially oleic acid, which can comprise over two-thirds of its lipid content. In addition, it provides significant levels of dietary fiber, fat-soluble vitamins such as A, D, E and K, carotenoids, tocopherols, and phytosterols like β-sitosterol. These constituents are consistently associated with antioxidant, anti-inflammatory, glycemic regulatory, and cardioprotective effects, supported by a growing body of experimental and clinical evidence. This review offers a comprehensive and critical synthesis of the chemical composition and functional properties of avocado, with particular emphasis on its lipid profile, phenolic compounds, and phytosterols. It also explores recent advances in environmentally sustainable extraction techniques, including ultrasound-assisted and microwave-assisted processes, as well as the application of natural deep eutectic solvents. These technologies have demonstrated improved efficiency in recovering bioactives while aligning with the principles of green chemistry. The use of avocado-derived ingredients in nanostructured delivery systems and their incorporation into functional foods, cosmetics, and health-promoting formulations is discussed in detail. Additionally, the potential of native cultivars and the application of precision nutrition strategies are identified as promising avenues for future innovation. Taken together, the findings underscore the avocado’s relevance as a high-value matrix for sustainable development. Future research should focus on optimizing extraction protocols, clarifying pharmacokinetic behavior, and ensuring long-term safety in diverse applications.

The growing emphasis on sustainability and circular economy strategies has driven increasing interest in the valorization of agro-industrial by-products. Among these, the peel and seed of avocado (Persea americana), typically discarded during processing, have emerged as promising sources of bioactive compounds, particularly phenolic constituents with recognized antioxidant capacity. This review critically examines the current scientific literature on the phytochemical composition, antioxidant activity, and potential health benefits associated with avocado peel and seed. In addition, it explores recent technological advances in extraction methods and highlights the applicability of these by-products in the formulation of functional foods, nutraceuticals, and other health-related products. Challenges related to safety, bioavailability, and regulatory aspects are also discussed. By consolidating available evidence, this work supports the potential of avocado peel and seed as valuable functional ingredients and contributes to sustainable innovation in the food and health industries.