Alpha-Bits, also known as Frosted Alpha-Bits, was a brand of breakfast cereal made by Post Consumer Brands, which contained frosted alphabet-shaped multi-grain (whole-grain oat and corn flour) cereal bits. Post Cereals also started producing "Marshmallow Alpha-Bits" in 1990.

Alpha-Bits cereal was invented by Thomas M. Quigley who worked for Post Cereals. The cereal was introduced in 1957 and was taken off the market in 2006. However, Alpha-Bits reappeared for sale in January 2008 with a new formulation, touting "0% Sugar!" as a "Limited Edition" cereal. The old recipe was reintroduced later in 2008. The cereal was substantially reformulated in 2017, with the "new and improved" Alpha-Bits having larger shapes than its predecessor. Alpha-Bits was discontinued in May 2021.