Prime rib is a beef cut that comes from the rib section of a cow, specifically the primal rib.

What prime rib actually is

  • Prime rib is another name for a standing rib roast, a large roast cut from the cow’s primal rib section.
  • It typically includes ribs 6 through 12 and contains the “eye” of the rib plus surrounding fat and connective tissue, which makes it very juicy and flavorful.

Beef, not pork or lamb

  • Despite the name “prime,” it does not mean it is always USDA Prime grade; it simply refers to the rib roast cut from beef.
  • You can find prime rib in different USDA grades (Prime, Choice, Select), but in all cases it is still a beef rib roast.

How people usually describe it

  • Many cooks describe prime rib as one of the most tender and rich-tasting beef roasts because of its generous marbling and fat cap.
  • When sliced into individual steaks from the same section, that same meat is sold as ribeye steaks, so prime rib and ribeye come from the same rib area of the cow.

TL;DR: Prime rib is a standing rib roast from the cow’s primal rib section (beef), not a different animal or special species of meat.

Information gathered from public forums or data available on the internet and portrayed here.