Sang Hongyang 桑弘羊 (152-80 BCE) was a high minister during the mid-Former Han period 前漢 (206 BCE-8 CE).
He hailed from Luoyang 洛陽 (modern Luoyang, Henan) and belonged to a merchant family. In 110 he was appointed overseer of the grain management (zhisu duwei 治粟都尉) and was shortly later made Chamberlain for the National Treasury (dasinong 大司農). He advocated the introduction of a state monopoly on the merchandise of salt, iron and liquors and supported the promotion of interregional trade in the Han empire. He installed the office of price control in the capital to prevent merchants from buying cheap and selling expensive. Sang Hongyang also advocated the sales of state offices against delivery of grain and the possibility for delinquents to buy themselves free.
He belonged to the group of persons that wanted to end the appeasement politics against the steppe federation of the Xiongnu 匈奴 by "harmonious marriage" (heqin 和親) with an imperial princess. Instead, military agro-colonies (tuntian 屯田) in the border region should prevent the hordes of the Xiongnu from staging raids on the ground of the empire. Yet Emperor Wu 漢武帝 (r. 141-87 BCE) did not approve the plan to increase the number of border garrisons.
When Emperor Zhao 漢昭帝 (r. 87-74 BCE) mounted the throne as a young boy, Sang Hongyang belonged to the four regents (sifu 四輔), together with Huo Guang 霍光, Shangguan Jie 上官桀 and Jin Midi 金日磾. Sang Hongyang occupied the post of Censor-in-chief (yushi dafu 御史大夫).
In 81 Emperor Zhao ordered collecting information about the performance of the state monopolies with the answer that the population heavily complained against the prices of salt and iron. The Emperor therefore convocated a large group of responsible officials and scholars to discuss the matter. A kind of protocol is included in Huan Kuan's 桓寬 book Yantielun 鹽鐵論. The monopoly was in the consequence given up.
Soon thereafter Sang Hongyang secretly conspired against Huo Guang and planned to overthrow Emperor Zhao. Their plot was reveiled, and both suffered execution.