Sunjo (Korean: 순조; Hanja: 純祖; 29 July 1790 – 13 December 1834), personal name Yi Gong (이공; 李玜), was the 23rd monarch of the Joseon dynasty of Korea.

Upon the death of his father, King Jeongjo, Yi Gong ascended to the throne at age 10 on 4 July 1800, lunar calendar.

During Jeonjo's reign, Lady Hyegyŏng was treated with respect and as the mother of King Jeongjo despite the fact that Lady Hyegyŏng was married to Crown Prince Sado who had been forced to commit suicide during the reign of Yeongjo, which had greatly affected Hyegyeong's status due to the controversy surrounding Sado's suicide.

[3] The Ogajaktongbeop (五家作統法), a census registration system to group five houses as one unit, was carried out in this period, and oppression against Catholicism began in earnest.

He was first buried next to Jangneung, Paju, the tomb of King Injo and Queen Inryeol but later moved to Illeung, Seoul as the Feng Shui at the old site was deemed to be unfavourable.