Sima Hui (died 208), courtesy name Decao and pseudonym Shuijing, was a hermit who lived during the late Eastern Han dynasty of China.

Sima Hui was from Yangzhai County (陽翟縣), Yingchuan Commandery, which is around present-day Yuzhou, Henan.

In Chapter 37 of the 14th-century historical novel Romance of the Three Kingdoms, Sima Hui, nicknamed Water Mirror, is described to be a carefree, wandering man who is well-versed in many arts.

Sima Hui is also featured in Chan Mou's manhua The Ravages of Time as the teacher of the "Eight Enigmas", a group of elite strategists and advisers.

Sima Hui is portrayed by Wang Shijun in the 2010 Chinese television series Three Kingdoms.