Yinreng (胤礽, born June 16, 1674; died January 27, 1725) was a Heir Apparent to the imperial throne of China. He was the second of the Kangxi Emperor's 20 sons to have survived into adulthood.

Yinreng's mother, Empress Xiaocheng (孝诚仁皇后) of the Heseri clan, a niece of Songgotu, died giving birth to him and was greatly lamented by Kangxi. The Emperor himself taught Yinreng to read and made Yinreng Heir Apparent when he was only two years old. Under a string of scholar-official tutors, the prince became well-versed in both Chinese and Manchu. In the years 1696 and 1697, when the Emperor was on campaign against Galdan of the Dzungars, Yinreng was both times made regent to look over affairs in Beijing. Despite scandals and suggestions of immorality, he remained in his father's favour and was given the Western Flower Garden (西花园).

In 1703 Yinreng's grand uncle Songgotu was imprisoned and died shortly afterwards. The Heir Apparent gradually fell into disfavour. In 1708, on the semi-annual hunting expeditions at Rehe, Kangxi charged Yinreng with immorality, impropriety, usurping power and treason. He was deprived of his position as Heir Apparent and imprisoned. When it was later discovered that the eldest prince Yinti had employed Lamas to cast evil spells on Yinreng, the latter was pardoned in 1709 and restored as Heir Apparent. In the ensuing three years Yinreng's condition became worse and the Emperor was convinced that he was insane. Consequently in 1712 he was again degraded and placed in perpetual confinement.

Yinreng died in prison in 1725, not long after his younger brother Yinzhen ascended the throne. He was posthumously made a Prince of the Blood with appellations of "Li" (理) and "Mi" (密). His son Hongxi was raised to a Prince of the Blood. The bitter factionalism between the sons of Kangxi and the dispute over the succession prompted the Yongzheng Emperor to establish the practice of placing the name of the chosen successor in a sealed box behind a tablet in the main hall of the Forbidden City. The name was made public only after the Emperor's death.