"Seongho" Yi Ik (1681–1763) was a Korean Neo-Confucian scholar, early Silhak philosopher and social critic.

Yi Ik followed in Yu Hyeong-won line of thought extending in this work Seongho Saseol, which covers subjects as government, economy, and the family, and makes detailed proposals for reordering each aspect of Joseon society.

His most famous work was Record of Concern for the Underprivileged which lays down the cardinal principles of reform ideas.

As Yi attracted many disciples, Silhak gradually emerged as Joseon dynasty's dominant school of thought.

In 1967 a monument to him, "Tomb of Yi Ik" was erect there, next to a museum celebrating his life and works.