国有化（英语：Nationalization），是将财产收归国家所有的行为。通常它指的是将大型涉及公共业务的私人企业国有化，但是有时它也指其它级别政府（比如地方政府）的公有财产。一般情况下国家会支付一定的金额来补偿原来的所有者，但是有的时候这个价格比市场价格要低很多，所以会造成原来所有者的损失。国有化的理由往往是因为某些产业（比如公共电力、石油、天然气、自来水等）或某些土地（如日本政府将钓鱼台列屿“收归国有”。）具有重要的战略作用。相似地，国有化的对立面通常是私有化，亦是左派和右派对经济政策的争论点。

Nationalization, or nationalisation, is the process of transforming private assets into public assets by bringing them under the public ownership of a national government or state. Nationalization usually refers to private assets or assets owned by lower levels of government, such as municipalities, being transferred to the state. The opposites of nationalization are privatization, municipalization and demutualization. Industries that are usually subject to nationalization include transport, communications, energy, banking and natural resources.