This chapter describes the main nutritional characteristics of algae and the current knowledge on their effects in poultry production with consideration to their impacts on animal health, growth performance, and product quality (eggs and meat). The chemical and nutritional value of algae is explored, along with extraction methods and the benefits of algae to animals. The authors then describe their impacts on laying hen production, covering egg productivity, quality and composition, as well as hens' health. Finally algae's effect on broiler chicken production is reviewed, covering growth performance, meat production and quality, and broiler health.