Abbott's booby (Papasula abbotti) is an endangered seabird of the sulid family, which includes gannets and boobies. It is a large booby and is placed within its own monotypic genus. It was first identified from a specimen collected by William Louis Abbott, who discovered it on Assumption Island in 1892.
Abbott's booby is the largest of all booby species, and is adapted to long-distance flight. Individuals can reach 80 cm from beak to tail, and weigh about 1.5 kg. It is distinguished from other sulids in the region by its black and white plumage; the only other bird with similar coloration and shape is the masked booby, which has an all-white body with black wings only. They have an off-white plumage, which contrasts with black eye patches, black wings and tails, and black flank marks. Their feet are blue and webbed, with black outer ends. Males have pale grey bills with a black tip, whereas females have pink bills with a black tip. Chicks have white down and a cape of black scapular feathers.