Cassinia compacta is a woody shrub that typically grows to a height of, its branches densely covered with erect glandular hairs. The leaves are linear, long and wide, dark green and sticky or scaly on the upper surface and hairy below. The flowerheads are about long and in diameter, each with five or six yellow florets surrounded by four or five overlapping whorls of golden-brown involucral bracts that are wrinkled near the tip. The heads are arranged in a dense corymb up to in diameter. Flowering occurs in spring and summer and the achenes are about long with a pappus long.