凋亡诱导因子（英语：Apoptosis-inducing factor，简称为AIF）是一类进化保守的黄素蛋白。凋亡诱导因子涉及到非胱天蛋白酶依赖型细胞凋亡途径的引发，可以使得细胞的染色体凝聚及DNA的片段化。同时它又扮演还原型烟酰胺腺嘌呤二核苷酸氧化酶的角色。凋亡诱导因子的另一个功能是在细胞凋亡时调节线粒体膜的通透性。它通常位于线粒体外膜从而与细胞核隔绝开来。然而，当线粒体受损时，凋亡诱导因子就会移动到胞质溶胶与细胞核中。

Apoptosis inducing factor is a flavoprotein.

Apoptosis inducing factor is involved in initiating a caspase-independent pathway of apoptosis (positive intrinsic regulator of apoptosis) by causing DNA fragmentation and chromatin condensation. It also acts as an NADH oxidase. Another AIF function is to regulate the permeability of the mitochondrial membrane upon apoptosis. Normally it is found behind the outer membrane of the mitochondria and is therefore secluded from the nucleus. However, when the mitochondrion is damaged, it moves to the cytosol and to the nucleus. Inactivation of AIF leads to resistance of embryonic stem cells to death following the withdrawal of growth factors indicating that it is involved in apoptosis.