逆向拍卖（Reverse auction）也称为荷兰式拍卖、减价拍卖、反向拍卖、出价（bidding）或招标（tendering）系统，有别于传统的正向拍卖的一卖方多买方形式，逆向拍卖指一种存有一位买方和许多潜在卖方的拍卖形式。在逆向拍卖中，买方会提出自己想要得到的商品，然后等待持有自己想要的商品的卖方的联系，潜在卖方持续喊出更低的价格，直到不再有卖方喊出更低价为止。适用于易失性物品的拍卖，例如飞机票、球赛门票等有时效性又怕卖不出去者。

A reverse auction is a type of auction in which the roles of buyer and seller are reversed. In an ordinary auction (also known as a forward auction), buyers compete to obtain a good or service by offering increasingly higher prices. In a reverse auction, the sellers compete to obtain business from the buyer and prices will typically decrease as the sellers underbid each other.