Fusu (died c. August or September 210 BC^[1]) was the eldest son and heir apparent of Qin Shi Huang, the First Emperor of the Qin dynasty.

After being deceived by two alchemists while seeking prolonged life, Qin Shi Huang supposedly ordered more than 460 scholars in the capital to be buried alive, though an account given by Wei Hong in the 2nd century added another 700 to the figure. Fusu counselled that, with the country newly unified and enemies still not pacified, such a harsh measure imposed on those who respect Confucius would cause instability.^[2] However, he was unable to change his father's mind and was instead sent to guard the frontier, where Meng Tian was stationed, in a de facto exile.

After the death of Qin Shi Huang, Fusu's youngest brother, Huhai, together with high officials Zhao Gao and Li Si, forged his father's decree to rename Huhai as the successor and order Fusu to commit suicide.^[3] Some aides of Fusu, including Meng Tian, doubted the veracity of the decree, but Fusu either did not believe someone would dare to forge the decree or, with good reason, feared being killed anyway and thus committed suicide.^{[citation needed]}

According to Records of the Grand Historian, Fusu had a son, Ziying, who was enthroned after Zhao Gao forced Huhai to commit suicide in 207 BCE. By that time, Li Si had already been eliminated by Zhao Gao. Ziying soon killed Zhao Gao.

There is no firm consensus on what Ziying's relationship to the Qin royal family really is. Some scholars (such as Wang Liqun) pointed out that Fusu's son might be too young to plot the demise of Zhao Gao, as two sons of Ziying, also involved in the plot, should have been old enough. Qin Shi Huang only lived to be 49; Fusu might have only lived into his 30s.

He sometimes appears as a door god in Chinese and Taoist temples, usually paired with Meng Tian.

• Sima, Qian. Records of the Grand Historian (Shiji).