云木香（学名：Saussurea costus），又名广木香或青木香，是一种菊及中药的一种。它们受到《濒危野生动植物种国际贸易公约》附录一的保护。

Saussurea costus, commonly known as costus or kuth, is a species of thistle in the genus Saussurea native to South Asia. Essential oils extracted from the root is used in traditional medicine and in perfumes since ancient times.

It has a large number of names in other languages, including kustha in Sanskrit; kust or qust in Arabic and Persian; kut, kur, and pachak in Hindi and Bengali, kostum, gostham, and potchuk in Tamil; upaleta and kur in Gujarati; kot or kust in Punjabi; changala in Telugu; sepuddy in Malayalam; kostha in Kannada; kuth or postkhai in Kashmiri; and koshet (קשט) in Hebrew.