Sima Jiong (司馬冏) (before 283 - 27 Jan 303), courtesy name Jingzhi (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 301. He was the fourth of the eight princes commonly associated with the War of the Eight Princes.