The Battle of the Ch'ongch'on River was a decisive battle in the Korean War along the Ch'ongch'on River Valley in the northwestern part of North Korea. In response to the successful Chinese First Phase Campaign, UN forces launched the Home-by-Christmas Offensive to expel the Chinese forces from Korea and to end the war. Anticipating this reaction, the Chinese People's Volunteer Army (PVA) Commander Peng Dehuai planned a counteroffensive, dubbed the "Second Phase Campaign", against the advancing UN forces.

Hoping to repeat the success of the earlier First Phase Campaign, the PVA 13th Army first launched a series of surprise attacks along the Ch'ongch'on River Valley on the night of November 25, 1950, effectively destroying the Eighth United States Army's right flank while allowing PVA forces to move rapidly into UN rear areas. In the subsequent battles and withdrawals during the period of November 26 to December 2, 1950, although the US Eighth Army managed to avoid being surrounded by PVA forces, the PVA 13th Army were still able to inflict heavy losses onto the retreating UN forces which had lost all cohesion. In the aftermath of the battle, the US Eighth Army's heavy losses forced all UN forces to retreat from North Korea to the 38th Parallel.