Rye (Secale cereale) is a grass grown extensively as a grain and forage crop. It is a member of the wheat tribe and is closely related to barley and wheat, although it is the singular species in the genus Secale. Rye grain is used to make flour, feed, some whiskeys and most vodkas. Rye, alone or overseeded, is planted as a livestock forage or harvested for hay. It is highly tolerant of soil acidity and is more tolerant of dry and cool conditions than wheat, though not as tolerant of cold as barley. The first possible use of domestic rye comes from the site of Tell Abu Hureyra in northern Syria, in the Euphrates Valley, dating to late Epi-Palaeolithic.

Rye was not one of the main cereals of Classical Antiquity. Probably it was only an accidental plant occurring in small numbers in most wheat fields. Since the middle ages, it is widely cultivated in Central and Eastern Europe and is the main bread cereal in most areas east of the French-German border and north of Hungary.

Rye straw is prized in Corn dolly making.