Goguryeo or Koguryo is one of the ancient Three Kingdoms of Korea, located in present-day northern and central parts of the Korean Peninsula, southern Manchuria, and southern reaches of Russia's Primorsky Krai.

Goguryeo is an active participant in the power struggle for control of the Korean peninsula and is also associated with the foreign affairs of neighboring polities in China and Japan.The Samguk Sagi, a 12th-century Goryeo text, indicates that Goguryeo was founded in 37 BCE by Jumong, a prince from Buyeo, although there is archaeological and textual evidence from Chinese geographic monographs that suggests Goguryeo culture was in existence since the 2nd century BCE around the fall of Gojoseon, an earlier kingdom that also occupied southern Manchuria and northern Korea.Goguryeo is a major dynasty in Northeast Asia, until it was defeated by a Silla-Tang alliance in 668.

After its fall, its territory is divided among Unified Silla, Balhae, and the Tang dynasty.The shortened name for Goguryeo is adopted by the Goryeo dynasty (918-1392), whose territory is in the southern portion of Goguryeo, and is the foundation of the English word "Korea."