The Crimson-backed Sunbird, Leptocoma minima (formerly Nectarinia minima), is a sunbird. The sunbirds are a group of very small Old World passerine birds which feed largely on nectar, although they will also take insects, especially when feeding young. Flight is fast and direct on their short wings. Most species can take nectar by hovering like a hummingbird, but usually perch to feed most of the time.

Crimson-backed Sunbird is an endemic resident breeder in the Western Ghats of India. Two eggs are laid in a suspended nest on a thin branch of low tree or shrub. They sometimes use the underside of large fern fronds to suspend their nests. This species is found in a variety evergreen woodland.

Crimson-backed Sunbirds are tiny, even by sunbird standards, and are only 8 cm long. They have medium-length thin down-curved bills and brush-tipped tubular tongues, both adaptations to their nectar feeding.

The adult male has a maroon breast-band, sides of the head and back. The throat is purple and the rump is crimson. rump are bright purple, and the underparts are yellow flanked with white. The male is similar to the larger Purple-rumped Sunbird, which occurs within this species restricted range, but lacks that species bright shoulder patch and white flanks. The call is chee-chee-which-chee.

The female has an olive-green back, brown wings and yellowish breast, like female Purple-rumped, but has a crimson rump.