闭花木属（学名：Cleistanthus）是大戟科下的一个属，为灌木或乔木植物。该属共有约140种，分布于东半球热带地区。

Cleistanthus is a plant genus of the family Phyllanthaceae first described as a genus in 1848. It is widespread in much of the Old World Tropics in Asia, Africa, Australia, and various oceanic islands. Cleistanthus collinus is known for being toxic and frequently used for homicidal or suicidal purposes.