Rye (Secale cereale) is a cereal, and is believed to have originated from a Central Asian wild grass, or from a wild rye found in Syria, Armenia, and Iran.

Rye has been regarded as an inferior grain and was referred to by the Roman author and philosopher, Pliny the Elder, as food only fit to avert starvation. Rye flour retains more nutrients than wheat due to the difficulty in separating the germ and bran from the endosperm of rye.

Rye was susceptible to the ergot fungus before the modern farming techniques today, and it is from the ergot fungus that the hallucinogenic drug LSD is synthesized.