Righteous armies (Korean: 의병), sometimes translated as irregular armies or militias, were informal civilian militias that appeared several times in Korean history, when the national armies were in need of assistance.

The Japanese invasions of Korea, commonly known as the Imjin War, involved two separate yet linked invasions: an initial invasion in 1592, a brief truce in 1596, and a second invasion in 1597. The conflict ended in 1598 with the withdrawal of Japanese forces from the Korean Peninsula after a military stalemate in Korea's southern provinces.