In 1995, what was supposed to be a small supporting role as the heroine’s silent, devoted bodyguard in ratings behemoth Sandglass turned Lee into a national heartthrob, such that his screen time was increased throughout the series’ run.

Lee’s acting breakthrough would come in late 1998 in the award-winning film An Affair by E J-yong. This was followed up by another success, City of the Rising Sun, for which he won Best Actor at the Blue Dragon Film Awards and the Korean Association of Film Critics Awards.

Though his time-travel romance Il Mare was not a popular success in 2000, since then it has developed a loyal fan base a la Somewhere in Time and attained the status of a minor classic among Korean cinema fans (Keanu Reeves played Lee’s role in the 2006 Hollywood remake The Lake House). Lee followed up with melodrama Last Present alongside Lee Young-ae and action mystery The Last Witness directed by Bae Chang-ho; both of which were considerable successes.

In 2003, he starred opposite Lee Beom-soo in Oh! Brothers, a comedy about two brothers, one of whom has an unusual disease. The film was one of Lee’s biggest hits ever, topping three million admissions at the local box office. Nonetheless he remained out of the limelight for the next couple years. Finally at the end of 2005 he returned in Typhoon, a big-budget action blockbuster by Kwak Kyung-taek, the director of Friend.

In August 2008, Lee was awarded his master’s degree from Dongguk University’s Department of Theater & Film Art in the Graduate School of Cultural Arts. He made his first foray into theater in December of that same year, taking on the titular role in Hamlet in Water. The play ran for four days at his alma mater’s Lee Hae-rang Theater.

Apart from his acting, Lee is known for launching a chain of upscale Italian restaurants in Seoul named after his movie Il Mare. Having studied interior design, he himself took responsibility for designing the interiors of his restaurants. Lee also founded the real estate development company Seorim C&D in 2008, and owns several businesses with actor Jung Woo-sung, his best friend since they starred together in City of the Rising Sun. In May 2016, Lee and Jung established and became CEOs of their entertainment label called the ‘Artist Company’.

El Fin del Mundo (“The End of the World”) is a 13-minute split screen film made by visual artists Moon Kyung-won and Jeon Joon-ho, which depicts the destructive environmental changes the world faces in the future and the subsequent end of art and birth of new art based on dialogue between two artists in different times and space, played by Lee and Im Soo-jung. The film was screened at dOCUMENTA in 2012, considered the world’s most prestigious and innovative contemporary art platform. A longtime art collector and honorary ambassador for the National Museum of Contemporary Art in 2011-2012, Lee also narrated the 2013 TV documentary Contemporary Art, Bury the Boundary which highlighted homegrown Korean artists.

Lee then portrayed Prince Suyang opposite Song Kang-ho in the period film The Face Reader (2013), for which he won Best Supporting Actor at the Blue Dragon Film Awards and the Baeksang Arts Awards. This was followed by action-comedy Big Match in 2014, where he played a mixed martial arts fighter trying to save his brother by winning an elaborate high-stakes game.

In 2015, he reunited with The Thieves director Choi Dong-hoon and actress Jun Ji-hyun in Assassination, set in 1930s Korea and Shanghai during the Japanese occupation. Lee won a Best Actor award at the 24th Buil Film Awards and was named Actor of the Year at the 3rd Marie Claire Asia Star Awards.

Lee’s films in 2017 include the historical epic Warriors of the Dawn and the fantasy blockbuster Along With the Gods: The Two Worlds.

In 2019, Lee starred in Svaha: The Sixth Finger, an occult film. The same year Lee madde drama comeback in ten years with the political drama Chief of Staff alongside Shin Min-a, where he plays a political advisor.