Wild rice, also called manoomin, mnomen, psíŋ, Canada rice, Indian rice, or water oats, is any of four species of grasses that form the genus Zizania, and the grain that can be harvested from them. The grain was historically and is still gathered and eaten in North America and, to a lesser extent, China, where the plant's stem is used as a vegetable.

Wild rice and domesticated rice (Oryza sativa and Oryza glaberrima), are in the same botanical tribe Oryzeae. Wild-rice grains have a chewy outer sheath with a tender inner grain that has a slightly vegetal taste.

The plants grow in shallow water in small lakes and slow-flowing streams; often, only the flowering head of wild rice rises above the water. The grain is eaten by dabbling ducks and other aquatic wildlife.

Three species of wild rice are native to North America:

One species is native to Asia:

Texas wild rice is in danger of extinction due to pollution and loss of suitable habitat in its limited range. The pollen of Texas wild rice can only travel about 30 inches away from a parent plant. If a receptive female flower receives no pollen, no seeds are produced. Manchurian wild rice has almost disappeared from the wild in its native range, but has been accidentally introduced into the wild in New Zealand and is considered an invasive species there.

The genomes of northern and Manchurian wild rices have been sequenced. There appears to be a whole-genome duplication after the genus split from Oryza.

The species most commonly harvested as grain are the annual species: Zizania palustris and Zizania aquatica. The former, though now domesticated and grown commercially, is still often gathered from lakes in the traditional manner, especially by indigenous peoples in North America; the latter was also used extensively in the past. The stems and root shoots also contain an edible portion on the interior.