The Least Tern (Sternula antillarum, formerly Sterna antillarum) is a species of tern that brees in North America and locally in northern South America. It is closely related to, and was formerly often considered conspecific with, the Little Tern S. albifrons of the Old World. Other close relatives include the Yellow-billed Tern S. superciliaris and Peruvian Tern S. lorata, both from South America.