Yi Ku
| Yi Ku | |
|---|---|
| Yi as a child | |
| Head of the House of Yi | |
| Period | May 1, 1970 – July 16, 2005 | 
| Predecessor | Crown Prince Yi Un | 
| Successor | Yi Won or Yi Seok or Yi Hae-won (disputed) | 
| Born | December 29, 1931 Kitashirakawa Palace (now former Grand Prince Hotel Akasaka), Kioicho, Kojimachiku, Tokyo, Empire of Japan | 
| Died | July 16, 2005 (aged 73) Grand Prince Hotel Akasaka, Kioicho, Kojimachiku, Tokyo, Japan | 
| Spouse | |
| Issue | Eugenia Unsuk (adopted) | 
| House | Yi | 
| Father | Crown Prince Yi Un of Korea | 
| Mother | Princess Masako of Nashimoto of Japan | 
| Religion | Roman Catholicism | 
| Occupation | Architect, businessperson | 
| Yi Ku | |
| Hangul | 이구 | 
|---|---|
| Hanja | 李玖 | 
| Revised Romanization | I Gu | 
| McCune–Reischauer | I Ku | 
| Imperial title | |
| Hangul | 황세손 | 
| Hanja | 皇世孫 | 
| Literal meaning | Prince Imperial | 
| Revised Romanization | Hwangseson | 
| McCune–Reischauer | Hwangseson | 
| Posthumous title | |
| Hangul | 회은황세손 | 
| Hanja | 懷隱皇世孫 | 
| Literal meaning | Prince Imperial Hoeun | 
| Revised Romanization | Hoeeun Hwangseson | 
| McCune–Reischauer | Hoeŭn Hwangseson | 
Yi Ku (Korean: 이구; December 29, 1931 – July 16, 2005) was a Korean prince who was head of the House of Yi from 1970 until 2005. He was a grandson of Emperor Gojong of the Joseon dynasty. Through Kuni Asahiko his maternal great-grandfather, Ku was a second-cousin to Emperor Emeritus Akihito of Japan.