Corn flakes, or cornflakes, are a breakfast cereal made from toasting flakes of corn (maize). Originally invented as a breakfast food to counter indigestion, it has become a popular food item in the American diet.

The cereal, originally made with wheat, was created by Will Kellogg in 1894 for patients at the Battle Creek Sanitarium where he worked with his brother John Kellogg who was the superintendent. The breakfast cereal proved popular among the patients and Kellogg subsequently started what became the Kellogg Company to produce corn flakes for the wider public. A patent for the process was granted in 1896, after a legal battle between the two brothers.

With corn flakes becoming popular in the wider community, a previous patient at the sanitarium, C. W. Post, started to make rival products. Kellogg continued to experiment with various ingredients and different grains. In 1928, he started to manufacture Rice Krispies, another successful breakfast cereal.

There are many generic brands of corn flakes produced by various manufacturers. As well as being used as a breakfast cereal, the crushed flakes can be a substitute for bread crumbs in recipes and can be incorporated into many cooked dishes.