Baekje or Paekche (18 BCE – 660 CE) is a kingdom located in southwest Korea.

It is one of the Three Kingdoms of Korea, together with Goguryeo and Silla.Baekje is founded by Onjo, the third son of Goguryeo's founder Jumong and So Seo-no, at Wiryeseong (present-day southern Seoul).

Baekje, like Goguryeo, claims to succeed Buyeo, a state established in present-day Manchuria around the time of Gojoseon's fall.Baekje alternately battles and allies with Goguryeo and Silla as the three kingdoms expand control over the peninsula.

At its peak in the 4th century, Baekje controls most of the western Korean peninsula, as far north as Pyongyang, and may have even held territories in China, such as in Liaoxi, though this is controversial.

It becomes a significant regional sea power, with political and trade relations with China and Japan.In 660, it is defeated by an alliance of Silla and Chinese Tang Dynasty, submitting to Unified Silla.