Ornithoptera priamus is sexually dimorphic.

Male: The upperside forewings are velvety black.
There is a green (most races) subcostal stripe and a green (most subspecies) marginal stripe bordering the termen, tormen and dorsum of the wing.
The sex brand is black and longish.
The underside of the forewing is black.
There is a chain of bluish or green postdiscal spots.

The hindwings are green.
At the wing's leading edge (costa) there are basal yellow-gold spots.
There is also a postdiscal chain of black spots.
The edge of the hindwing is black.

The underside is dark green or bluish.
The yellow-golden spots are transparent.
The veins are partly black and the marginal edge of the wing is black.
At the outer edge there is a postdiscal chain of black spots.

The body (abdomen) is yellow.
Head and thorax are black.
The underside of thorax has a red hair coat.

Female: The female is larger than the male and in the upper range of the wingspan.
The basic colour of the female is dark brown.
There is a chain of white postdiscal spots on the forewings.
There is a chain of larger white postdiscal spots with dark centres on the hindwing.
The underside is very similar to the upper.

Larva: First instar larvae are wine red on hatching.
They soon turn black or dark brown.
All segments have soft tubercles with stiff ends bearing black spines.
On the 4th segment tubercles are red.
The tubercles are dark brown on the other segments.
In the second instar, the tubercles lack spines, the 4th tubercles are light red and on the other segments they are the same colour as the body.
In the third instar, there is a white to pink saddlemark on the 4th segment.
In the fourth and fifth instars, the ground colour is ashy grey to brown, the saddlemark on the 4th segment is white and the tubercles on the 4th segment are white.
There may be saddlemarks on the 5th segment and the 6th segment.
The tips of the tubercle are black and the osmeterium is dark red.

Pupa: The pupa is yellowish green or brown and is marked with greyish veins as in a leaf.
It may have a broad dorsal pale saddle mark.
The abdomen has eight pairs of sharp dorsal processes, directed laterally.
Ornithoptera priamus is sexually dimorphic.
Male: The upperside forewings are velvety black. There is a green (most races) subcostal stripe and a green (most subspecies) marginal stripe bordering the termen, tormen and dorsum of the wing. The sex brand is black and longish. The underside of the forewing is black. There is a chain of bluish or green postdiscal spots.
The hindwings are green. At the wing's leading edge (costa) there are basal yellow-gold spots. There is also a postdiscal chain of black spots. The edge of the hindwing is black.
The underside is dark green or bluish. The yellow-golden spots are transparent. The veins are partly black and the marginal edge of the wing is black. At the outer edge there is a postdiscal chain of black spots.
The body (abdomen) is yellow. Head and thorax are black. The underside of thorax has a red hair coat.
Female: The female is larger than the male and in the upper range of the wingspan. The basic colour of the female is dark brown. There is a chain of white postdiscal spots on the forewings. There is a chain of larger white postdiscal spots with dark centres on the hindwing. The underside is very similar to the upper.
Larva: First instar larvae are wine red on hatching. They soon turn black or dark brown. All segments have soft tubercles with stiff ends bearing black spines. On the 4th segment tubercles are red. The tubercles are dark brown on the other segments. In the second instar, the tubercles lack spines, the 4th tubercles are light red and on the other segments they are the same colour as the body. In the third instar, there is a white to pink saddlemark on the 4th segment. In the fourth and fifth instars, the ground colour is ashy grey to brown, the saddlemark on the 4th segment is white and the tubercles on the 4th segment are white. There may be saddlemarks on the 5th segment and the 6th segment. The tips of the tubercle are black and the osmeterium is dark red.
Pupa: The pupa is yellowish green or brown and is marked with greyish veins as in a leaf. It may have a broad dorsal pale saddle mark. The abdomen has eight pairs of sharp dorsal processes, directed laterally.
Ornithoptera priamus