Typically, the wingspan of a spicebush swallowtail ranges from 7.6 to 10.2 cm. Adults are primarily black/brown in color, with a trademark green-blue (male) or bright blue (female) splotch in the shape of a half moon on the hindwings. The forewing has a border of cream-colored, oval spots. In the middle portion of the wing, the spots can be moon shaped and a light blue in color. Both sexes have cream-yellow moon-shaped spots on the edges of the hindwings and a bright, orange spot at the base of the wings. In females, the orange spot at the base of the wings will turn a greenish-white shade in summer, but not the spring. On the underside of the hindwing, there will be a dual row of orange spots, which distinguishes it from the pipevine swallowtail, which only has a single row of spots. In between these rows, there is more blue or green coloring.
This primarily black swallowtail is normally found in deciduous woods or woody swamps, where they can be found flying low and fast through shaded areas. Females tend to stay in open plains, while males are typically found in swamp areas.