Emperor Ai of Jin, personal name Sima Pi (司馬丕), courtesy name Qianling (千齡), was an emperor of the Eastern Jin Dynasty. During his brief reign, the actual powers were largely in the hands of his granduncle Sima Yu the Prince of Kuaiji, and the paramount general Huan Wen. According to historical accounts, he had an obsession with immortality, which resulted in his death, brought about as a result of poisoning by pills given to him by magicians in 364 and in 365.

The Jin dynasty or the Jin Empire, sometimes distinguished as the Sima Jin (司馬晉) or the Two Jins (兩晉), was an imperial dynasty in China that existed from 266 to 420. It was founded by Sima Yan, eldest son of Sima Zhao, who had previously been declared the King of Jin. There are two main divisions in the history of the dynasty. The Western Jin (266–316) was established as the successor to Cao Wei after Sima Yan usurped the throne from Cao Huan and took the title of Emperor Wu. The capital of the Western Jin was initially in Luoyang, though it later moved to Chang'an. In 280, after conquering Eastern Wu, the Western Jin ended the Three Kingdoms period and reunited China proper for the first time since the end of the Han dynasty.