Elachistocleis is a genus of microhylid frogs found in southern America from Panama southwards.

[1][2] A 2021 study found that the genus originated in the Andes during the Oligocene, and contains two distinct clades that diverged from one another during the Middle Miocene.

The name has been applied to many Elachistocleis populations across South America, which are all now considered to represent undescribed species (with one of these from Trinidad and northern Venezuela being described as E. nigrogularis in 2021).

In addition, another Elachistocleis identified from Trinidad in a 1980 study likely represents another undescribed species.

[3] The following species are recognised in the genus Elachistocleis:[1] Caramaschi, 2010 Kwet & Di-Bernardo, 1998 Jowers, Othman, Borzée, Rivas, Sánchez-Ramírez, Auguste, Downie, Read & Murphy, 2021 Toledo, 2010 Nunes-de-Almeida and Toledo, 2012 (Dunn, Trapido, and Evans, 1948) (Ruthven, 1914) Caramaschi & Jim, 1983 Lavilla, Vaira & Ferrari, 2003 Caramaschi, 2010