酰化反应或称(酰基化反应)，为有机化学中，氢或者其它集团被酰基取代的反应，而提供酰基的化合物，称为酰化剂。

酰化反应，可依攻击的亲核试剂不同，可分为：氧酰化反应、氮酰化反应、碳酰化反应。

In chemistry, acylation (rarely, but more formally: alkanoylation) is the process of adding an acyl group to a compound. The compound providing the acyl group is called the acylating agent.

Because they form a strong electrophile when treated with some metal catalysts, acyl halides are commonly used as acylating agents. For example, Friedel-Crafts acylation uses acetyl chloride (ethanoyl chloride), CH₃COCl, as the agent and aluminum chloride (AlCl₃) as a catalyst to add an ethanoyl (acetyl) group to benzene: