The Long-billed Starthroat, Heliomaster longirostris, is a hummingbird that breeds from southern Mexico to Panama, from Colombia south and east to Bolivia and Brazil, and on Trinidad. It is present throughout South and Central America and is an uncommon but widespread species, which appears to be a local or seasonal migrant, although its movements are not well understood.

The Long-billed Hummingbird's greatest range is east of the Andes and covers the entire Amazon Basin and northern South America including the Guianas.

This hummingbird inhabits forest, and is usually seen in woodland clearings, but will sometimes visit gardens. The female Long-billed Starthroat lays two eggs in a small cup nest in a tree.

The Long-billed Starthroat is 10.2 cm long and weighs 6.8 g. The black bill is straight and very long, at about 3.5 cm. The male has bronze-green upperparts, a blue crown, white moustachial stripe and reddish throat. The underparts are grey shading to white on the flanks and mid-belly, and the tail is mainly black. The female is similar, but has a green crown and a purple-edged black throat.

Long-billed Starthroats feed on nectar, taken from a variety of flowers, and some insects. The song of this species while feeding is a light weet.