A steak is a thick cut of meat generally sliced across the muscle fibers, sometimes including a bone. It is normally grilled or fried. Steak can be diced, cooked in sauce, such as in steak and kidney pie, or minced and formed into patties, such as hamburgers.

Steaks are cut from animals including cattle, bison, buffalo, camel, goat, horse, kangaroo, sheep, ostrich, pigs, turkey, and deer, as well as various types of fish, especially salmon and large fish such as swordfish, shark, and marlin. For some meats, such as pork, lamb and mutton, chevon, and veal, these cuts are often referred to as chops. Some cured meat, such as gammon, is commonly served as steak.

Grilled portobello mushroom may be called mushroom steak, and similarly for other vegetarian dishes. Imitation steak is a food product that is formed into a steak shape from various pieces of meat. Grilled fruits such as watermelon have been used as vegetarian steak alternatives.

Exceptions, in which the meat is sliced parallel to the fibers, include the skirt steak cut from the plate, the flank steak cut from the abdominal muscles, and the silverfinger steak cut from the loin and including three rib bones. In a larger sense, fish steaks, ground meat steaks, pork steak, and many more varieties of steak are known.

In the United States, steak cut from cattle is also called "beefsteak".