Adult killdeer reach a length ranging between 23-27cm, with an average wingspan of 17.5 cm. Distinguishing characteristics include a dark, double-banded breast, with the top band completely encircling the upper body/breast. Another band is located at the head, resembling a mask absent of the facial portion. The band is continuous, thinning while going across the face along the forehead region and above the bill, and thickening at the supercilium; extending around the eye and onward around the back of the head. Plumage is relatively absent of complexity with the exception of a vividly colored, reddish-orange rump that is visible during flight and behavioral displays. The rest the body consists of a grayish-brown coloration along the dorsal side, crown and nape, while the ventral region is white. Characteristic of species in the same order, Charadrius vociferus possess a lengthened tarsus and a pointed, extended bill, suitable for its foraging habits.

Male and female killdeer are similar in appearance, though breeding females may have additional brown on their face. Juvenile killdeer are similar in appearance to adults, with the exception of buffed fringes and the (uncommon) presence of tail-down.

There are three recognized subspecies of Charadrius vociferus. These subspecies are differentiated on the basis of differences in coloration and pattern of rufous edgings on their back and wing coverts. ("National Geographic Society. Field Guide to the Birds of North America", 1987; Hayman, Marchant, and Tony, 1986; Jackson and Jackson, 2000)