[3][4] French ornithologist Louis Pierre Vieillot described the white-throated hummingbird in 1818 as Trochilus albicollis.

[5] Ludwig Reichenbach erected the genus Leucochloris in 1854, deriving the name from the Ancient Greek leukos "white" and chloros "green".

Adults have a medium length, straight, bill with a blackish maxilla and red mandible with a black tip.

Juveniles have grayish brown underparts with less white and brownish tips to the tail feathers.

[6] The white-throated hummingbird is found in eastern Paraguay, southeastern Brazil from Minas Gerais and Espírito Santo south, Uruguay, and northeastern Argentina.

It inhabits semi-open to open landscapes such as the edges of mature forest, marshes, scrublands, parks, and gardens.

[6] The white-throated hummingbird forages for nectar at a very wide variety of native and introduced plants.