Okjeo was Korean tribal state which arose in the northern Korean peninsula from perhaps 2nd century BC to 5th century AD.
Dong-okjeo (Eastern Okjeo) occupied roughly the area of the Hamgyŏng provinces of North Korea, and Buk-okjeo (Northern Okjeo) occupied the Duman River region.
Dong-okjeo was often simply called Okjeo, while Buk-okjeo was also sometimes referred to as Chiguru (置溝婁, 치구루) or Guru (구루), the latter name being also applied to Goguryeo. Okjeo bordered the other minor state of Dongye on the south, and shared a similar fate.
In its early history, Okjeo oscillated between domination by the Chinese commanderies and by Goguryeo. From the 3rd century BC to 108 BC, it was controlled by Gojoseon due to the constant interference of its neighbors, Okjeo never grew into a fully centralized kingdom.
Our knowledge of Okjeo culture is fragmentary. As with the Dongye and Okjeo's language, food, clothing, architecture, and customs were similar to that of Goguryeo. The Okjeo people practiced arranged marriage by which the child-bride lived with the child-groom's family until adulthood, and they interred the dead of a family in a single coffin.