The Devon is a traditional British breed of beef cattle. It originated in, and is named for, the county of Devon in the West Country of England. It is a deep rich red in colour, and so may be known as the Devon Ruby or Red Ruby; it may also be called the North Devon to distinguish it from the South Devon.

Beef cattle are cattle raised for meat production. The meat of mature or almost mature cattle is mostly known as beef. In beef production there are three main stages: cow-calf operations, backgrounding, and feedlot operations. The production cycle of the animals starts at cow-calf operations; this operation is designed specifically to breed cows for their offspring. From here the calves are backgrounded for a feedlot. Animals grown specifically for the feedlot are known as feeder cattle, the goal of these animals is fattening. Animals not grown for a feedlot are typically female and are commonly known as replacement heifers. While the principal use of beef cattle is meat production, other uses include leather, and beef by-products used in candy, shampoo, cosmetics, and insulin.