Bak Gyusu (Korean: 박규수; 1807–1877) was a scholar-bureaucrat, teacher, politician, and a diplomat of the Joseon period.

[1] In 1848, he successfully passed the Gwageo civil service exam, a test required for government work.

Gyusu decided to instruct Pak Yung-hio in his ways of enlightened thinking after he took initiative and sought the politician out.

Bak Gyusu was the governor of Pyongan province when the General Sherman incident occurred, an event commonly cited as a factor important to the end of Korean isolationism in the 19th century.

The ship's crew ignored his warning and captured the messenger adjutant-general Yi Hyon-Ik, a subordinate of Bak Gyusu.