The French term cordon bleu is translated as "blue ribbon".^[4] According to Larousse Gastronomique, the cordon bleu "was originally a wide blue ribbon worn by members of the highest order of knighthood, L'Ordre des chevaliers du Saint-Esprit, instituted by Henri III of France in 1578. By extension, the term has since been applied to food preparation to a very high standard and by outstanding cooks. The analogy no doubt arose from the similarity between the sash worn by the knights and the ribbons (generally blue) of a cook's apron."^[5][6]

The origins of cordon bleu as a schnitzel filled with cheese are in Brig, Switzerland,^[7] probably about the 1940s, first mentioned in a cookbook from 1949. The earliest reference to "chicken cordon bleu" in The New York Times is dated to 1967, while similar veal recipes are found from at least 1955.^[6]

There are many variations of the recipe involving cutlet, cheese, and meat. A popular way to prepare chicken cordon bleu is to butterfly cut a chicken breast, place a thin slice of ham inside, along with a thin slice of a soft, easily melted cheese. The chicken breast is then rolled into a roulade, coated in bread crumbs, and then deep-fried.^[8] Other variations exist with the chicken baked^[9] rather than fried.

Other common variations include omitting the bread crumbs,^[10] wrapping the ham around the chicken, or using bacon in place of ham.^[11]

A similar dish popular in the Asturias province of Spain is cachopo, a deep-fried cutlet of veal, beef or chicken wrapped around a filling of Serrano ham and cheese.^[12] In Spain, a version made usually with just two slices of ham and cheese, although it can also be found with chicken or pork loin added, is often called san jacobo.

A common variant in Uruguay and Argentina is the milanesa rellena. It consists of two beef or chicken fillets passed through beaten egg, later, stuffed with cooked ham and mozzarella cheese and superimposed like a sandwich. Once this is done, they are again passed through beaten eggs and breadcrumbs, to be fried or baked. It is usually served with papas fritas (french fries) as a garnish.

In largely Muslim-populated countries, halal versions of chicken cordon bleu are also popular: the chicken is rolled around beef or mutton instead of pork.