Avocado seed waste has increased as avocado products have become commercialized since the seed is considered inedible. However, by exploring the potential uses of the seed, the unrecyclable waste produced by the avocado industry can be reduced. This paper aims to review and discuss current literature on the food and cosmetic applications of avocado seeds and their constituents. In descending order, avocado seeds contain starch, water, lipids, protein, phytochemicals, antinutrients, vitamins, and minerals. As for food applications, starch can be used as a bioplastic, flour, thickening agent, and emulsifier. Additionally, extracts containing avocado seed phytochemicals show antimicrobial and preservative activities, which can find use in meat products and in producing an orange dye. When considering cosmetic applications, patented avocado seed extract formulations have proven useful in skincare. Also, the avocado seed lipids, in the form of fatty acids, can be processed into soap. By applying the ideas presented in this review, the toll avocado seeds take on the environment would be reduced, improving the sustainability of the avocado market. As a result, avocado seeds can contribute to the emerging bioeconomy market for food and cosmetic applications.