Sima Jiong (司馬冏) (before 283[1] – 27 Jan 303[2]), courtesy nameJingzhi (景治), formally Prince Wumin of Qi (齊武閔王), was an imperial prince of the Jin dynasty of China. He briefly served as Emperor Hui's regent after overthrowing the usurper Sima Lun in May 301. He was the fourth of the eight princes commonly associated with the War of the Eight Princes.
^Although Sima Jiong's birth year was not recorded, his father Sima You was born in 246. Thus, Sima Jiong's birth year should be between 259 and 270.
^According to the Book of Jin, Sima Jiong was defeated on the wu'chen day of the 12th month of the year after the 1st year of the Yong'ning era of Emperor Hui's reign. This corresponds to 27 Jan 303 in the Julian calendar. [永甯元年....。明年十二月戊辰，冏败...] Jin Shu, vol. 29. Volume 84 of Zizhi Tongjian indicated that the battle to subdue Jiong began on the ding'mao day of that month, which corresponds to 26 Jan 303 (Emperor Hui's biography in Book of Jin also dated the start of the battle to that day), and lasted for 3 days. The volume also indicated that Jiong was executed very quickly after the battle ended. Thus, according to Tongjian, Jiong probably died on 29 Jan 303 (i.e. the geng'wu day of that month).