Song Seung-heon began his career in 1995 as a model for the jeans brand STORM, and first became known to viewers in the popular sitcom Three Guys, Three Girls in 1996. The following year he started his extremely successful career in TV dramas, which made him well known throughout Korea. His feature film debut came in 1999 in the film Calla together with star Kim Hee-sun.

True stardom only came to Song in late 2000, however, with the broadcast of the hugely popular TV drama Autumn in My Heart. The series was exported all over Asia, making pan-Asian and Korean Wave stars of both him and co-stars Song Hye-kyo and Won Bin. Since then he has been actively recruited for film roles and advertisements in Japan, Hong Kong and other Asian countries.

In 2002, Song starred in the comic-action film Make It Big by director Cho Ui-seok, and also in the Hong Kong film So Close with Hong Kong actresses Karen Mok, Shu Qi and Zhao Wei. He also starred in Summer Scent with Son Ye-jin, the third “season-themed” Yoon Seok-ho TV drama after Autumn in My Heart and Winter Sonata; Summer Scent did not become as popular as the ones that preceded it.

In 2004 Song appeared in two films, but neither was judged to be a success: Ice Rain, shot in the Canadian Rockies, failed to enthuse viewers with its mixture of mountaineering and melodrama, while He Was Cool, based on an internet novel by Guiyeoni, proved unable to compete with Harry Potter and the Prisoner of Azkaban and other films from the 2004 summer season.

Meanwhile in late 2004, just as he was getting ready to start shooting another high profile TV drama Sad Love Story, it was revealed that the actor had illegally avoided his compulsory military service by submitting tainted urine samples that suggested he was suffering from certain illnesses and was thus unfit for the army. Amidst the press coverage and scandal this aroused, Song agreed to immediately serve his two-year term in the military. Song was discharged on November 15, 2006 with the rank of Corporal, to much fanfare and media attention. For a time he kept a low profile, trying to gauge public opinion on his return to the entertainment world.

For his comeback, Song took on a tough image, playing aggressive and masculine roles in the 2008 drama East of Eden, where he won an award. He also started the 2008 film Fate, and the 2010 remake A Better Tomorrow.

His popularity in Japan continued, and in 2010 he starred in Ghost remake Ghost: In Your Arms Again with Matsushima Nanako.

In 2011 Song returned to television in My Princess opposite Kim Tae-hee, his first romantic comedy. He considers the series a turning point in his career, saying, “Previously, I took on characters living a life full of ups and downs.