A hoop skirt or hoopskirt is a women's undergarment worn in various periods to hold the skirt extended into a fashionable shape. Hoop skirts typically consist of a fabric petticoat with casings to hold a stiffening material, variously rope, osiers, whalebone, steel or nylon.
Lightweight hoop skirts, usually with nylon hoops, are worn today under very full-skirted wedding gowns. They can sometimes be seen in the gothic fashion scene. They are also an essential part of American Civil War reenactment.