Lee Wan-yong was born into the Ubong Yi clan (우봉 이씨; 牛峰李氏) to a poor aristocrat family in 1858, but grew up with a lot of support after he became the adoptive son of Yi Ho-jun, who was a friend of Heungseon Daewongun and an in-law.

He learned English and theology at Yookyoung Park, went to the United States to live as a diplomat, and returned to Korea to serve as a pro-Russian politician until the 1896 Agwan Pacheon incident, where King Gojong and his crown prince took refuge at the Russian legation in Seoul.

[2] Lee was a founding member of the Independence Club established in 1896 and belonged to the "reform faction" which wanted to Westernize Korea and to open the country to foreign trade.

Under Japanese Resident-General Itō Hirobumi, Lee was promoted to the post of prime minister from 1906 to 1910.

He was rewarded with a peerage in the Japanese kazoku system, becoming a hakushaku (Count), in 1910, and was raised to the title of kōshaku (Marquis) in 1921.