During World War II the Norwegian resistance movement (both civilian resistance and some pockets of military resistance that did not surrender in 1940) remained very active throughout the war.

Norwegian resistance kept many German divisions tied down in occupation duty and Norwegian spotters led to the destruction of numerous German warships. The Norwegian resistance also smuggled people in and out of Norway during the war and also managed to snatch the world's supply of heavy water and also destroy a heavy water plant, not so much preventing the Germans from developing an atomic bomb as helping the United States to do so themselves. However, the Germans had to revolt Resistance activities and killed several innocent, Norwegian men after any Resistance act. Some resistance acts have also been considered as war crimes

See also: Weserübung, British campaign in Norway, Vidkun Quisling