Heo Jun (허준, 1537?/1539 – 9 October 1615) was a court physician of the YangcheonHeo clan during the reign of King Seonjo of the Joseon Dynasty in Korea. He was appointed as a court physician at the age of 29. He wrote a number of medical texts, but his most significant achievement is Dongui Bogam (lit. "Mirror of Eastern Medicine"), which is often noted as the defining text of traditional Korean medicine. The work spread to East Asian countries like China, Japan, and Vietnam where it is still regarded as one of the classics of Oriental medicine today. Although Heo Jun worked extensively with the royal family, he put a great emphasis on making treatment methods accessible and comprehensible to common people. He found natural herb remedies that were easily attainable by commoners in Korea. Furthermore, he wrote the names of the herbs using the simple hangul letters instead of using more difficult hanja (Chinese characters), which most commoners did not understand.
Heo Jun's name and accomplishments are widely recognized by Koreans even today. Korean people still refer to Heo Jun's natural remedies found in his Dongui Bogam.
Portrayed by Jun Kwang-ryul in 1999-2000 MBC TV series Hur Jun, which reached record-breaking viewership ratings of 64%. In the series, Heo Jun was a youngster who worked as a helper with no relevant tasks, until he was mentored by Yoo Ui-tae, a doctor who taught him medicine and inspired him to become a doctor for and of the people. In reality, Yoo Ui-tae was younger than Heo Jun by about 100 years.