Lee Myong-Seung (also Lee Myeong-Seung, Korean: 이 명승; born August 14, 1979 in Seoul) is a South Korean marathon runner. He set a personal best time of 2:13:25, by finishing ninth at the 2010 Seoul International Marathon. In the same year, he achieved his best career result with a fourth-place finish at the Gyeongju International Marathon, clocking at 2:16:19. Lee made his official debut for the 2004 Summer Olympics in Athens, where he placed forty-first out of a hundred runners in the marathon, with a time of 2:21:01.