Wonjong of Joseon or Prince Jeongwon (2 August 1580 – 2 February 1619) was a prince during the Joseon dynasty. He was a son by a concubine to the Joseon dynasty's 14th monarch, king Seonjo, and half brother of king Gwanghaegun and father of king Injo. His birth name was Yi Bu (이부; 李琈).

He first held the title of Prince Jeongwon (定遠君, 정원군) and later re-titled as Grand Internal Prince Jeongwon (定遠大院君, 정원대원군). In 1592, during the Japanese invasions of Korea, he escaped with his father, King Seonjo and awarded in 1604 in recognition of helping the king to escape.