Who Was Lee Yong Joo, the Late Korean Actor Who Starred in "Princess Hours"?

South Korean actor Lee Yong Joo, best known to many international K-drama fans for his role in Princess Hours, has died at 44. News of his sudden passing was announced by a close friend on August 29, with South Korean media reporting that he died from cardiac arrest.

For viewers who remember him from the early days of Korean dramas becoming a staple among Filipino audiences, Yong Joo had a career that stretched across film, television, and comedy. Here are five things to know about the late actor.

Born in 1982, Lee Yong Joo began his career as a model before moving into acting. According to MyDramaList, he studied Sports at Kyungwon University and made his official acting debut in 2004 in the historical film Doma Ahn Jung-geun.

He later appeared in the MBC sitcom Hello, Franceska, where he began gaining recognition as a supporting actor. His television credits eventually grew to include dramas and sitcoms such as Ugly Young-Ae, The Women's Room, 12 Years Promise, My Unfortunate Boyfriend, Golden Pouch, and Less than Evil.

For international K-drama fans, one of Yong Joo’s most recognizable credits was Princess Hours, the 2006 MBC romantic drama starring Yoon Eun Hye, Ju Ji Hoon, Kim Jeong Hoon, and Song Ji Hyo.

Yong Joo played Jang Kyung, a high school friend of Crown Prince Lee Shin, played by Ju Ji Hoon. While he was not one of the drama's central characters, his role placed him in one of the era's most widely watched Korean dramas.

Princess Hours remains particularly familiar to Filipino viewers, having become one of the Korean dramas that helped fuel the local appetite for Hallyu television in the 2000s.

Yong Joo’s most significant career breakthrough came several years later with tvN’s Blue Tower, a military comedy series that premiered in 2013.

He played Private Lee Yong-joo, a clumsy and somewhat hapless new recruit whose comedic misadventures became a major part of the show's appeal. According to The Chosun Daily, the role became one of the performances for which he was best remembered.

The character was also notable because of the contrast between the demands of the role and Yong Joo’s own circumstances. Although he convincingly portrayed a new recruit, he had actually been exempted from mandatory military service because of a heart condition.

Yong Joo had previously opened up about his health. In February 2026, he appeared on fellow actor Lee Jong Hyuk’s YouTube channel, where he discussed having a heart condition and explained that it had led to his exemption from military service.

According to outlets like AsiaOne, Yong Joo had been diagnosed with hypertrophic cardiomyopathy, a condition in which the heart muscle becomes abnormally thick. He had also shared that his mother had been hospitalized with the same disease and that he was diagnosed after undergoing a medical examination following his doctor’s advice.

In his later years, Yong Joo stepped back from acting and explored other work. According to MyDramaList, he effectively retired from acting in 2022 to focus on private business ventures.

His path outside entertainment was not always straightforward. In the 2026 interview with Lee Jong Hyuk, he shared that a business venture in Busan had failed, prompting him to return to Seoul and start over. He said he was running a one-person travel agency near Moran Market in Seongnam.

Yong Joo’s final public appearance came through that YouTube interview, where he spoke about his life, work, and health alongside fellow actors. Following the news, colleagues remembered Yong Joo for his warmth off-camera as much as his work onscreen.

Rest in peace, Lee Yong Joo.