重商主义（英语：mercantilism；也称作商业本位，16至18世纪）是16～17世纪封建主义解体之后西欧资本原始积累时期的一种经济理论或经济体系，该名称最初是由亚当·斯密在《国民财富的性质和原因的研究》（《国富论》）一书中提出来的。学术界代表人物是斯图尔特，政界的著名代表人物是法国路易十四的大臣让-巴普蒂斯特·柯尔贝尔，柯尔贝尔主义（Colbertism）是重商主义的一个变种。

这一时期商业资本兴起，促使封建自然经济瓦解，各国国内市场统一，并通过对殖民地的掠夺和对外贸易的扩张积累了大量货币财富，推动了工场手工业发展，因而产生了代表商业资本利益和要求的重商主义经济思想。

Mercantilism was an economic theory and practice, dominant in modernized parts of Europe during the 16th to the 18th century, that promoted governmental regulation of a nation's economy for the purpose of augmenting state power at the expense of rival national powers. It was the economic counterpart of political absolutism or absolute monarchies. Mercantilism includes a national economic policy aimed at accumulating monetary reserves through a positive balance of trade, especially of finished goods. Historically, such policies frequently led to war and also motivated colonial expansion. Mercantilist theory varies in sophistication from one writer to another and has evolved over time. High tariffs, especially on manufactured goods, are an almost universal feature of mercantilist policy. Other policies have included