Wonder Bread is an American brand of sliced bread. Established in Indianapolis, Indiana, in 1921, it was one of the first companies to sell sliced bread nationwide by 1930. The brand is currently owned by Flowers Foods in the United States.

Sliced bread is a loaf of bread that has been sliced with a machine and packaged for convenience, as opposed to the consumer cutting it with a knife. It was first sold in 1928, advertised as "the greatest forward step in the baking industry since bread was wrapped". By 1933, around 80% of bread sold in the US was pre-sliced, leading to the popular idiom "greatest thing since sliced bread".