The yellow perch has a yellow to brass-colored body and distinct pattern, consisting of five to 9 olive-green, vertical bars, triangular in shape, on each side. Its fins are lighter in coloration, with an orange hue on the margins.
The body is laterally compressed. The anterior portion of the body is deep, gradually tapering into a slender caudal peduncle. The opercle is partially scaled, and a single spine is present on the posterior margin.
As with all percid fishes, yellow perch have two dorsal fins. The anterior is convex in shape and consists of 11-15 spines. The posterior dorsal fin has a straight margin, consisting of one or two spines and 12-16 rays.
The nape, breast, and belly of yellow perch are all fully scaled. A complete lateral line (50-70 scales) is present. The anal fin consists of two spines and six to 9 rays. A single spine and five rays make up the pelvic fins, and the pectoral fins consist of 13-15 rays. The caudal fin of the yellow perch is forked.