Oflag XXI-C was a German Army World War II prisoner-of-war camp for officers (Offizierlager) located in Ostrzeszów in German-occupied Poland. It held mostly Norwegian officers arrested in 1942 and 1943, but also Dutch, Italian, Serbian and Soviet POWs. Originally most Norwegian soldiers and officers had been released after the end of the Norwegian campaign, but as resistance activities increased, the officers were rearrested and sent to POW camps.