贸易保护主义，通常简称保护主义（英语：Protectionism），是一种为了保护本国产业免受国外竞争压力而对进口产品设定极高关税、限定进口配额或其它减少进口额的经济政策。它与自由贸易模式正好相反，后者使进口产品免除关税，让外国的产品可以与国内市场接轨，而不使它们负担国内制造厂商背负的重税。

贸易保护主义经常被人们与重商主义和进口替代联系起来。重商主义认为保持一个可观的贸易顺差对一个国家是很有利的。

取决于是否征收关税，贸易保护主义有两个分支：传统贸易保护主义（有意征收关税）和现代贸易保护主义（无意征收关税）。

In economics, protectionism is the economic policy of restraining trade between states (countries) through methods such as tariffs on imported goods, restrictive quotas, and a variety of other government regulations designed to allow (according to proponents) fair competition between imports and goods and services produced domestically. According to their proponents, protectionist policies protect the businesses and workers within a country by restricting or regulating trade with foreign nations. In recent years, protectionism has manifested itself through popular anti-globalization and anti-immigration movements.