producer, manufacturer - someone who manufactures something

Kellogg, W. K. Kellogg, Will Keith Kellog - United States food manufacturer who (with his brother) developed a breakfast cereal of crisp flakes of rolled and toasted wheat and corn; he established a company to manufacture the cereal (1860-1951)

C. W. Post, Charles William Post, Post - United States manufacturer of breakfast cereals and Postum (1854-1914)