The Three Kingdoms of Korea refer to the Korean kingdoms of Goguryeo, Baekje and Silla, which dominate the Korean peninsula and parts of Manchuria for much of the 1st millennium CE.

The Three Kingdoms period runs from 57 BCE until Silla's triumph over Goguryeo in 668, which marks the beginning of the North and South States period of Unified Silla in the South and Balhae in the North.The earlier part of this period, before the three states developed into full-fledged kingdoms, is sometimes called the Proto-Three Kingdoms of Korea.