Scallions (green onion, spring onion and salad onion) are vegetables of various Allium onion species. Scallions have a milder taste than most onions. Their close relatives include the garlic, shallot, leek, chive, and Chinese onion.

Although the bulbs of many Allium species are used as food, the defining characteristic of scallion species is that they lack a fully developed bulb. In common with all Allium species, scallions have hollow, tubular green leaves, growing directly from the bulb. These leaves are used as a vegetable; they are eaten either raw or cooked. The leaves are often chopped into other dishes, in the manner of onions or garlic. Also known as scallions or green onions, spring onions are in fact very young onions, harvested before the bulb has had a chance to swell.