后连合（英语：Posterior commissure）是脑白质束之一。它通过脑的中线，位于中脑导水管上端的背侧。后连合的功能与瞳孔对光反射有关。目前尚不清楚后连合具体连接脑的那些部位。后连合中的神经纤维多数源自“后连合核”。后连合核是一个位于动眼神经核前的核团。后连合的其他神经纤维可能来自丘脑的后部，以及上丘。另外的神经纤维可能与内侧纵束中的纤维相连。也有一些纤维可能连接两侧的被盖前核。

Template:连合纤维与隔

The posterior commissure (also known as the epithalamic commissure) is a rounded band of white fibers crossing the middle line on the dorsal aspect of the upper end of the cerebral aqueduct. It is important in the bilateral pupillary light reflex.

Its fibers acquire their medullary sheaths early, but their connections have not been definitively determined. Most of them have their origin in a nucleus, the nucleus of the posterior commissure (nucleus of Darkschewitsch), which lies in the central gray substance of the upper end of the cerebral aqueduct, in front of the oculomotor nucleus.