Protectionism is the economic policy of protecting powerful domestic industries through the use of high tariffs and other regulations to discourage imports. Often nations will resort to protectionism in retaliation for perceived subsidies or some other unfair trade advantage. Protectionism differs from economic sanctions only in that there is no wider political objective. Applied generally, it is the opposite of a free trade policy.

Multinational and international trade treaties like NAFTA and the FTAA seek to deter protectionism, as does the World Trade Organization in its ongoing GATT negotiations.

Variations of this of this policy have been known as mercantilism, import substitution, and economic nationalism.