The butterfly, like other insects, has three pairs of legs and its body is divided into three sections: head, thorax, and abdomen. Its length ranges from a few millimeters to about 100 mm. The wingspan can reach, in the larger species, up to 300 mm.

The head bears a pair of antennae, a pair of compound eyes, palps (which are the main sensory organs), and a mouth in the form of a long proboscis, folded like a coil, used for sucking nectar. The thorax is mainly responsible for the butterfly's movement, and on it are three pairs of legs and two pairs of wings. The butterfly's wings are built from a transparent membranous surface on which many colorful scales are laid, like roof tiles, giving the butterfly its color.

The abdomen contains mainly the butterfly's internal organs, the digestive and excretory tubes, the reproductive system, most of the circulatory system, and the tracheae - a respiratory organ unique to insects.