Lee Se-In (born June 16, 1980) is a South Korea football player who plays for Chinese club Tianjin Songjiang. His previous club is Daejeon Citizen, Gangwon FC and Busan I'Park. He also played for Changchun Yatai in the Chinese Super League.
He scored debut and second goal consecutively came on 13 May 2009, against National League side Incheon Korail in the first round of Korean FA Cup 2009.
On 9 January 2010, Lee transferred to Changchun Yatai. On 8 July 2011, he joined Busan I'Park.