Animal-based proteins are the most consumed worldwide given their well-balanced nutritional composition. However, the growing demand for animal proteins will not be sustainable due to their low conversion efficiency and high environmental footprint. Specific consumers’ dietary restrictions and modern trends emphasize the importance of finding alternative sustainable non-animal sources to meet future food (and, in particular, protein) global needs. Algal biomass is considered a relevant alternative, presenting advantages over terrestrial biomass such as higher growth rate, low water consumption, no competition for arable land, carbon–neutral emissions, and production of numerous bioactive compounds. This review provides an overview of recent research advances on algae as source of proteins, including production strategies from relevant protein-producing species. Partic- ular emphasis will be given to algae protein current applications and forthcoming challenges of their use. Nutritional and functional aspects of algae biomass or its protein-enriched fractions will be overviewed.