韭葱（别名扁葱或京葱）为葱科葱属的栽培作物。在历史上，韭葱曾被赋予多种生物学学名，但目前通常认为其是象大蒜的栽培品种。

多年生宿根草本，一般作二年生栽培；叶子扁而宽，叶鞘粗肥白嫩，层层包裹，呈圆筒形，称“葱白”；淡紫色花，丛集成球状，生于花茎顶端。

The leek is a vegetable that belongs, along with onion and garlic, to the genus Allium, currently placed in family Amaryllidaceae, subfamily Allioideae. Historically, many scientific names were used for leeks, which are now treated as cultivars of Allium ampeloprasum. The name 'leak' developed from the Anglo-Saxon word leac. Two related vegetables, elephant garlic and Kurrat, are also cultivars of A. ampeloprasum, although different in their uses as food.