Red junglefowl are the wild ancestors of all domestic poultry, although the rooster is said to be more brilliantly coloured than its tame relative. The vibrant male has long, golden-orange to deep-red crown and neck feathers, and a dark metallic-green tail with a white tuft at the base. The underparts are a dull black while the upper parts are a combination of glossy blue-green, rich dark red, maroon-red, fiery orange, rufous and blackish brown. The colourful cock also has vivid scarlet-red facial skin, throat, two lappets and heavily dented fleshy crest (comb), and red or white ear patches on the sides of the head. The rather drab female is a dull brown-gold colour with a partly naked, pale red face and throat. After the summer moult, from June to September, the male develops an ‘eclipse plumage', in which the golden neck feathers (hackles) are replaced with dull black feathers, the long tail feathers are lost, and the comb reduces in size and becomes duller in colour. With much hybridization between pure and domestic stock, the standard criteria of pure wild junglefowl include the tail being carried horizontally in both sexes, the absence of a comb in the female, and dark or slate grey leg colour and an annual eclipse moult in the male.

There are five subspecies, which vary in the colour of the facial lappets, in the size of the combs, and in the length, colour and terminal end shape of the neck hackles of males during the breeding season.