The Bureau of Interpreters or Sayŏgwŏn was an agency of the Joseon government of Korea from 1393 to 1894 responsible for training and supplying official interpreters. Textbooks for foreign languages produced by the bureau aimed to accurately describe contemporary speech and are thus valuable sources on the history of Korean and the various foreign languages.

In a country surrounded by linguistically distinct neighbours, Korean diplomacy has always relied on interpreters. They were a vital part of the national foreign policies of sadae 'serving the great' (i.e. China) and gyorin 'neighbourly relations'. King Chungnyeol of Goryeo established the T'ongmun'gwan (通文館 'Office of Interpretation') in 1276 to train interpreters in Chinese and (possibly) Mongolian.

In 1393, the second year of the Joseon period, the Bureau of Interpreters was established as part of the Ministry of Rites. Regulations stipulated that its director would be an official of the principal third rank. The bureau operated until 1894, when it was abolished as part of the Gabo Reforms. The bureau was based in buildings to the west of the Six Ministries in the central district of the capital, Hanyang (modern Seoul). The site is marked by a plaque on Saemunan-ro 5-gil behind the Sejong Center for the Performing Arts.

A memorial from 1394 mentions instruction in Chinese and Mongolian. The most important and most taught language was always Chinese, reflecting Korea's key foreign relationship and the sadae policy. Each year, three or four delegations were sent to the Chinese court, including about 20 official interpreters. Some of the most promising students were included, to give them immersive practice.

The study of Mongolian had originally been introduced when Goryeo was a vassal state of the Mongol Yuan dynasty. After the collapse of the Mongol empire, Joseon Korea had few dealings with the Mongols, but Mongolian language skills were retained as a strategic measure, in case the Mongols should again rise and threaten Korea.

Japanese and Jurchen became regular subjects in 1414 and 1426 respectively. Together, these were known as the 'four studies' (Sahak 四學), with Jurchen later being succeeded by Manchu. The Jianzhou Jurchen (the Manchus) invaded Korea in 1627 and 1637, before overthrowing the Ming in 1644 and establishing the Qing dynasty in China. From then on, the Manchu language (viewed by Koreans as a later form of Jurchen) was ranked next to Chinese by the Bureau.

The bureau was responsible for training interpreters, with about 100 students in the 15th century, increasing to over 200 in the 18th century, In addition, branch schools were established near the frontiers in the early 15th century:

A school was established on Jeju Island in 1671, teaching Chinese and Japanese. There were no local schools for Mongolian until the late 19th century, as there were no Korean contacts with the Mongols.