吖丁啶（Azetidine）是一种环状化合物，由一个氮原子杂环丁烷组成，化学式C₃H₇N。

吖丁啶可通过1,3-丙二胺在盐酸中加热生成。

Azetidine is a saturated heterocyclic organic compound containing three carbon atoms and one nitrogen atom. It is a liquid at room temperature with a strong odor of ammonia and is strongly basic compared to most secondary amines. Azetidines do not occur as frequently in nature and have been studied far less than closely related chemical compounds such as pyrrolidine and β-lactam.