Gu Yong (168–243), courtesy nameYuantan, was a minister of the state of Eastern Wu during the Three Kingdoms period. He learnt the classics and calligraphy from Cai Yong when the latter came to Wu briefly as a refugee. His family is one of the four illustrious houses of Wu (Zhu, Lu, Gu, Zhang). He became a governor of several prefectures throughout Yang Province. He was successful in pacify and integrate rebels and minorities under his jurisdiction.
When Sun Quan became the 'King of Wu', he bestowed the title of "Marquis of Yangsui District" (陽遂鄉侯) on Gu Yong. After Sun Quan declared himself 'Emperor' and established Wu in 229, Gu Yong was appointed as the chancellor.
Gu Yong was said to be a reticent person and a teetotaler, famous for his standards of personal conduct; whenever he spoke, however, he spoke with confidence and reason. He was also known for keeping silent when he disagreed with something; this was a major reason why the emperor often tested his ideas on Gu Yong to see what Gu thought of the concepts — if Gu Yong refused to comment Sun Quan would realise something had not been thought through. Gu Yong was a very modest person who did not repay his enemies with malice but always did everything according to the law.