Prince Nakcheon (Korean: 낙천군; Hanja: 洛川君; November 26, 1720 – September 28, 1737) was a royal family member of the Joseon dynasty. His name was Yi On (이온; 李縕) while he was originally named Yi Susin (이수신; 李守愼);[1] his courtesy name was "Onjung" (온중; 蘊仲).[2]
Prince Nakcheon was by birth the only son of Yi Chae (이채; 李埰),[3] and he later became an adoptive son of late Prince Yeollyeong in 1734.[1]