The least sandpiper is the smallest shorebird. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-colored waterside birds. The specific minutilla is Medieval Latin for "very small".

Waders or shorebirds are birds of the order Charadriiformes commonly found wading along shorelines and mudflats in order to forage for food crawling or burrowing in the mud and sand, usually small arthropods such as aquatic insects or crustaceans. The term "wader" is used in Europe, while "shorebird" is used in North America, where "wader" may be used instead to refer to long-legged wading birds such as storks and herons.