Heungseon Daewongun (24 January 1821 – 22 February 1898) was the title of Yi Ha-eung, the regent of Joseon during the minority of Emperor Gojong in the 1860s. Until his death, he was a key political figure of late Joseon Korea. Daewongun literally translates as "prince of the great court", a title customarily granted to the father of the reigning monarch when that father did not reign himself (usually because his son had been adopted as heir of a relative who did reign). While there had been three other Daewonguns during the Joseon dynasty, there was no one as dominant as Yi Ha-Eung in the history of the Joseon dynasty that the term Daewongun usually refers specifically to him.

Joseon was going through changes in many aspects during this period, but was for the most part unable to keep up with the rapidly changing situation the country found itself in. Yi Ha-eung, had to solve both the looming threat posed by Western nations, which were continuously encroaching upon the sovereignty of Eastern states, while at the same time attempt to rebuild a country ravaged by poverty and internal power struggles. He is remembered both for the wide-ranging reforms he attempted during his regency, as well as for what was described by historian Hilary Conroy as "vigorous enforcement of the seclusion policy, persecution of Christians, and the killing or driving off of foreigners who landed on Korean soil"