South Korean actor Lee Yong-joo, best known for his memorable role in the tvN military comedy series Blue Tower, has died at the age of 44.
Lee Yong-joo died suddenly on August 29, 2026, with South Korean media reporting that the actor suffered a heart attack. News of his death was initially shared by people close to him, leaving family members, colleagues and fans mourning an actor remembered for bringing humor to Korean television.
His sudden death has also brought renewed attention to a heart condition Lee had discussed publicly years earlier. The actor previously revealed that he had been diagnosed with hypertrophic cardiomyopathy, a condition that resulted in his exemption from South Korea’s mandatory military service.
However, while Lee’s previous heart condition has resurfaced following his death, reports have not established that hypertrophic cardiomyopathy directly caused the heart attack associated with his passing.
What Happened to Lee Yong-joo?
Lee Yong-joo died on Saturday, August 29, at the age of 44.
According to reports from South Korean media, the actor’s death was sudden and his cause of death was reported as a heart attack.
An acquaintance announced Lee’s passing on social media, explaining that the unexpected nature of his death had left those close to him struggling to process the news.
The circumstances were made even more difficult because Lee’s phone was password-protected, reportedly making it challenging for his family to immediately contact everyone who had known or worked with him.
Friends consequently appealed for people within the entertainment industry and Lee’s wider circle to help spread the news so that those who knew him could learn of his passing.
What Was Lee Yong-joo’s Cause of Death?
Lee Yong-joo’s cause of death has been reported as a heart attack.
Following the announcement, attention quickly turned toward the actor’s previous disclosure that he had hypertrophic cardiomyopathy.
Lee discussed the condition publicly in 2013 while speaking about why he had not completed mandatory military service.
He explained that his mother had previously been hospitalized with hypertrophic cardiomyopathy. Doctors reportedly suggested that the condition could be hereditary, leading Lee and his sister to undergo testing.
Lee said he was subsequently found to have the same condition as his mother.
Despite that medical history, it is important to distinguish between Lee’s previous diagnosis and the circumstances surrounding his death.
At this time, no direct causal relationship between his hypertrophic cardiomyopathy and his reported heart attack has been publicly confirmed.
Who Was Lee Yong-joo?
Lee Yong-joo was a South Korean actor and former model who built a career across television and film.
Born in 1982, Lee entered the entertainment industry as a model before transitioning into acting during the 2000s.
His early acting work included a minor role in the 2004 film Doma Ahn Jung-geun. He later appeared in several recognizable Korean television productions, gradually becoming a familiar face to viewers.
His television credits included Hello, Francesca, Princess Hours, Ugly Miss Young-ae, Let’s Eat, Golden Tower and other productions.
However, the role most closely associated with Lee Yong-joo was his appearance in tvN’s Blue Tower.
Lee Yong-joo’s Role in ‘Blue Tower’
Lee became particularly popular through his portrayal of the awkward and lovable new recruit Lee Yong-joo in Blue Tower.
The military comedy became one of his defining projects and introduced him to a wider television audience.
His performance was especially notable considering that Lee himself had never completed military service because of his medical exemption.
Rather than preventing him from convincingly portraying the character, his performance helped make the inexperienced new recruit one of the show’s recognizable personalities.
Lee continued appearing within the Blue Tower franchise, including Blue Tower Zero and Blue Tower Returns.
Years later, he also appeared in the 2022 ENA military comedy New Recruit.
Lee Yong-joo Also Appeared in ‘Princess Hours’
International K-drama viewers may also recognize Lee Yong-joo from Princess Hours, also known as Goong.
The hugely popular 2006 romantic comedy helped introduce Korean dramas to audiences across several countries.
Lee appeared as Jang-kyung, one of Crown Prince Lee Shin’s high school friends.
His association with Princess Hours has resurfaced following news of his death, particularly among international viewers who remember the drama.
Lee Yong-joo Had Previously Spoken About His Heart Condition
Long before his death, Lee had openly discussed living with hypertrophic cardiomyopathy.
During interviews connected with Blue Tower in 2013, he explained that the diagnosis resulted in his exemption from military service.
According to Lee’s account, doctors recommended testing after his mother was hospitalized with the same condition.
He and his sister underwent medical examinations, and Lee said he was the sibling found to have inherited the condition.
The revelation has received renewed attention following reports that he died from a heart attack.
However, Lee’s previous diagnosis and his reported cause of death should not automatically be treated as medically connected without confirmation from his family or appropriate medical authorities.
What Was Lee Yong-joo Doing Before His Death?
Lee had stepped away from the level of television activity that characterized some of his earlier years, but he remained connected to the entertainment industry.
Earlier in 2026, he appeared on actor Lee Jong-hyuk’s YouTube channel and provided viewers with an update on his life.
Lee revealed that he was operating a one-person travel agency in Seongnam, specializing in package tours.
The appearance showed a different side of his life outside acting and indicated that he had moved into the travel business while continuing to be remembered for his television career.
That update came only months before news of his sudden death.
‘Blue Tower’ Colleagues Mourn Lee Yong-joo
News of Lee Yong-joo’s death prompted emotional tributes from actors who had worked alongside him.
Among those remembering him was his Blue Tower colleague Kim Jae-woo, who recalled Lee as a passionate actor who genuinely cared about the people around him.
Other colleagues associated with the series, including Baek Bong-ki, Kim Ho-chang, Jeong Jin-wook and Song Young-jae, also expressed condolences following his passing.
The reaction demonstrated the relationships Lee had developed during his years working in Korean entertainment, particularly among the cast members associated with the project that became his best-known work.
Lee Yong-joo Funeral Arrangements
Lee Yong-joo’s funeral altar was established in Room 5 at the Bundang Jesaeng Hospital Funeral Hall in Seongnam, Gyeonggi Province, South Korea.
His funeral procession was scheduled for 6:30 a.m. on August 31.
According to funeral information reported by South Korean media, Lee will be laid to rest through the Seongnam City Funeral Culture Center.
His sudden death has left friends and relatives dealing with an unexpected loss while fans continue to revisit the television roles through which they came to know him.
Remembering Lee Yong-joo
Lee Yong-joo spent more than two decades working across modeling, film and television.
Although he appeared in numerous productions, Blue Tower became an especially important part of his career.
His portrayal of an inexperienced but endearing new recruit gave audiences a character that remained associated with him years after the series aired.
For international K-drama audiences, appearances in productions such as Princess Hours provide another connection to an actor whose career crossed different periods of Korean television.
Lee Yong-joo was only 44 when he died.
As tributes continue, his colleagues and viewers are remembering him not simply for the circumstances surrounding his death, but for the performances and humor he brought to audiences throughout his career.
Disclaimer
This article is based on publicly available information and media reports concerning the death of Lee Yong-joo. His cause of death has been reported as a heart attack. Lee had previously disclosed that he was diagnosed with hypertrophic cardiomyopathy, but no direct causal connection between that condition and his death has been publicly confirmed. Medical details should therefore not be inferred beyond information released by appropriate sources. Funeral arrangements and other details may be updated if additional verified information becomes available. This article is intended for informational and memorial purposes and should not be treated as an official medical report or statement from the family.