The First and Second Battles of Wonju (French: Bataille de Wonju), also known as the Wonju Campaign or the Third Phase Campaign Eastern Sector[nb 4] (Chinese: 第三次战役东线; pinyin: Dì Sān Cì Zhàn Yì Dōng Xiàn), was a series of engagements between North Korean and United Nations (UN) forces during the Korean War. The battle took place from December 31, 1950 to January 20, 1951 around the South Korean town of Wonju. In coordination with the Chinese capture of Seoul on the western front, the North Korean Korean People's Army (KPA) attempted to capture Wonju in an effort to destabilize the UN defenses along the central and the eastern fronts.
After a joint Chinese People's Volunteer Army (PVA) and KPA assault breached the UN defenses at Chuncheon on New Year's Eve of 1951, KPA V Corps attacked US X Corps at Wonju while KPA II Corps harassed US X Corps' rear by engaging in guerrilla warfare. In response, US X Corps under the command of Major General Edward Almond managed to cripple the KPA forces at Wonju, and the UN forces later carried out a number of anti-guerrilla operations against the KPA infiltrators. In the aftermath of the battle, the KPA forces on the central and the eastern fronts were decimated, allowing the UN front to be stabilized at the 37th parallel.