Breakfast cereal is a food product designed especially to be marketed to consumers as a breakfast food. Though cereal is a staple of daily meals in many countries around the world, in wealthier, consumer-conscious nations such as the United States, entire industries have been created dedicated to the sale of specialized products, such as breakfast cereals. Breakfast cereals are generally eaten cold and mixed with milk as opposed to hot cereals like oatmeal, grits, etc.

Breakfast cereals are marketed to all ages. For adults, companies such as Kellogg's, Quaker Oats, and General Mills promote their products for the health benefits gained from eating oat-based and grain-based cereals. Nevertheless, the vast majority of breakfast cereal sold is marketed to young children. Cereal manufacturers have been criticized for manufacturing breakfast cereals with a heavy sugar content aimed at children. Sugar-laden breakfast cereals have been extremely popular with children for decades, and many adults also buy them out of nostalgia (also because they enjoy the taste). Manufacturers often fortify breakfast cereals with various vitamins.