The skirt steak is a cut of beef steak from the plate (belly) primal cut. It is a long, flat cut that is flavorful, but tougher than most other steak cuts. It is the cut of choice for making fajitas ("little belts" or "sashes" in Spanish) and Cornish pasties. Skirt steaks are usually marinated or braised over low heat. Skirt steak should be sliced across the grain for serving.

In the United States, whole skirt steak has the meat-cutting classification NAMP 121. The more tender inner skirt (NAMP 121D) is attached to the rib cage (ribs 6-12), while the tougher outer skirt (NAMP 121C) consists of the diaphragm muscle and an attached thick membrane which must be removed before cooking.