"Protein deficiency and environmental deterioration are pressing and complex issues in traditional agriculture system. Algae, which can grow without the need of land and with minimal water, offer a rich source of protein. Recently, large-scale algae cultivation and advanced extraction techniques have been developed, positioning algae protein as a promising alternative to traditional animal proteins in various food categories. This review explores the global development of algae protein in the food industry, emphasizing its potential in association with animal protein or as a substitute for animal protein in foods. It highlights the importance of algae protein extraction and quality in food structuring and nutrition. Algae protein can be tailored to create a wide range of food products, though its properties are not fully understood and depend on cultivation conditions and extraction methods. Currently, the utilization of algae protein can be achieved through the use of entire biomass or of protein concentrates, which may contain a variety of proteins and non-protein components. Despite the challenges associated with non-purified algae protein, the field is advancing toward efficiently extracting protein from the algae matrix and incorporating it into new food matrices. This progress makes the application of algae protein in “blue foods” increasingly promising. However, like plant proteins, algae protein faces the dual challenges of sustainability and functionality."