Sun Jun (219[2] – 19 October 256),[a] courtesy name Ziyuan, was a military general and regent of the state of Eastern Wu during the Three Kingdoms period of China.
He served under the second Wu emperor, Sun Liang.
In 253, after Zhuge Ke had suffered a major military defeat to Wu's rival state, Cao Wei, and subsequently refused to admit fault but instead tried to wipe out all dissent, Sun Jun assassinated him and took over as regent.
In 256, at the urging of Wen Qin, a Wei general who had surrendered to Wu after a rebellion of his and Guanqiu Jian's failed, Sun Jun considered launching a major attack against Wei, but as he was about to do so, he grew ill.
He transferred his powers to his cousin Sun Chen and then died.