American physician and health-food pioneer whose development of dry breakfast cereals (breakfast cereal) was largely responsible for the creation of the flaked-cereal industry.

Kellogg received his M.D. from Bellevue Hospital Medical College, New York City, in 1875. A Seventh-day Adventist and vegetarian, Kellogg became superintendent in 1876 of the Seventh-day Adventist Western Health Reform Institute, which then became the Battle Creek Sanitarium. (In 1959 it was renamed the Battle Creek Health Center.) Kellogg developed numerous nut and vegetable products to vary the diet of the patients, including a flaked-wheat cereal called Granose and cornflakes. Although cornflakes were not new, they had never before been presented as a breakfast food. Kellogg's (Kellogg, W K) brother W.K. Kellogg formed his own cereal company, and one of the sanitarium patients, C.W. Post (Post, C W), also founded a cereal company that became well known.

Kellogg was founder and first president (1923–26) of Battle Creek College, and in 1931 he opened Miami-Battle Creek Sanitarium at Miami Springs, Fla. He was also the author of numerous medical books.