The conspicuous male Flame Robin has a bright orange-red breast and throat that extends close to the bill and contrasts with a dark slate-grey head, throat and back. There is a clear white stripe on the folded wing and white on the lower belly and undertail. There is a small white forehead patch. The bill is black and the legs dark brown. The female is grey-brown, lighter underneath and has a pale buff wing stripe and a mostly white outer tail feather.
The Flame Robin's preferred habitat type is forests and woodlands up to about 1800 m above sea level. In winter, birds move to lower and more open areas, including gardens. Some Tasmanian birds move to the mainland.
Flame Robins feed on insects, spiders and other small arthropods. Like all Australasian robins, they are perch and pounce hunters, often returning to a favourite low perch several times to stand erect and motionless, scanning the leaf-litter for more prey. They are typically seen in pairs during the spring and summer breeding season or in loose companies in more open country during winter.
Breeding occurs from August to January. The nest, built by the female, is a neat grass, moss and bark cup, bound with spider web and decorated with lichen. It is normally placed in a cavity or fork in a tree. Three to four pale green or blue eggs, spotted with brown marks, are laid. The female incubates the eggs while the male supplies her with food. Both sexes feed the young chicks. The Flame Robin may lay up to two clutches during one breeding season.