Lee enrolled in the Department of Theater at Chung-ang University in Seoul in 1988. He made his acting debut in the 1990 film Kurae, Kakkumun Hanulul Boja (Yes, Let’s Look Up At the Sky Now and Again). Following his debut, he appeared in films including The Ginkgo Bed, City of the Rising Sun, The Anarchists, Jungle Juice and Wet Dreams, but it was the 2003 film Singles that made him rise to stardom. The Korean press has dubbed him “The Little Giant of Chungmuro” (Korean equivalent of Hollywood). He received a 2011 Seoul Art & Culture Award for best TV drama actor for his role in Giant.

Lee Beom-soo got married for the first time in 2003 but divorced after four months. In 2010, he married Lee Yoon-jin, an English interpreter, who taught him English.[3] Shortly after the May ceremony, they announced that they were expecting their first child. Their daughter, So-eul (소을), was born on March 1, 2011. On February 21, 2014 their first son was born.