Oflag XXI-B, World War II prisoner camp in Szubin, Poland.

Oflag XXI-B was a German military prisoner camp in Szubin consisting of barracks and administration buildings arranged around a former Polish school. The facility was secured with barbed wire fences and guard towers, holding a capacity of over 1,400 people.

In September 1939 the Germans opened a camp at Szubin for Polish civilians seized in the Intelligenzaktion; from October 1939 Polish POWs were held in Kriegsgefangenenlager Schubin, built by adding barracks around a Polish boys' school. Stalag XXI-B2 was formally established in December 1939, and Oflag XXI-B for Allied officers followed in September 1940 with French prisoners. In March 1943, 35 men escaped through a tunnel but none reached neutral territory; the camp was cleared in April 1943 and later reopened as Oflag 64 for American officers.

The camp drew officers from many Allied air forces, including the RAF, RCAF, RAAF, RNZAF, SAAF and USAAF, as well as airmen from occupied Poland and Czechoslovakia. Prisoners included Wing Commander Harry Day, Senior British Officer from November 1942 to March 1943, and serial escaper Josef Bryks of the Czechoslovak RAFVR. British prisoners who died at the camp were later buried at the Commonwealth War Graves Commission cemetery in Poznań.

The site is located in a smaller town and can be difficult to reach during winter months, so visitors should be flexible with their plans. Researching local guided tours or museum offerings beforehand helps visitors understand the history more deeply when they arrive.

In March 1943, 35 prisoners escaped through a tunnel, but none reached neutral territory. The camp was then cleared of all POWs in April 1943, most sent to the enlarged Stalag Luft III. It was later reopened as Oflag 64 for American officers.