It occurs in the New World from the southwestern United States and Mexico to Argentina, and also on Trinidad and Tobago, the Bahamas and the Greater Antilles.

Small and plump, with a fairly short, sharp-pointed beak and bright yellow eyes, it typically appears quite dark all over.

Least grebes are found in a wide variety of wetland habitats, including freshwater ponds, lakes, and marshes, slow-flowing streams and rivers, roadside ditches, and mangrove swamps.

[4][7] In general, they prefer bodies of water with significant amounts of vegetative cover, particularly along the edges; they will even use wetlands which are almost completely overgrown.

[4] They may choose small, temporary bodies of water to breed, in an effort to avoid predation of their chicks by large fish.

[10] Those in the tropics tend to breed during the rainy season, while active nests have been found in every month of the year in Texas.

[8] Each pair builds a compact floating nest of vegetation—typically a variety of aquatic weeds—which is anchored to rooted plants in still open water as deep as 1.5 m (4.9 ft).