What is the osprey related to?

Ospreys are related to hawks, eagles, and kites, collectively called raptors. They belong to the taxonomic order Accipitriformes, which includes both diurnal raptors like ospreys and nocturnal birds of prey such as owls. Ospreys are placed within the family Pandionidae, which contains only one genus, Pandion, and just the single species Pandion haliaetus.