Official History of New Zealand in the Second World War 1939–45

The Official History of New Zealand in the Second World War 1939–45 is a 48-volume series published by the War History Branch (and its successors) of the Department of Internal Affairs which covered New Zealand involvement in the Second World War. The series was published during the period 1949 to 1986. A collection of booklets entitled Episodes and Studies were also published between 1948 and 1954. The Official History of New Zealand in the Second World War 1939–45 was the largest publication project undertaken in New Zealand.

It had long been felt in New Zealand that the four-volume 'popular' history of the New Zealand Expeditionary Force, the Official History of New Zealand's Effort in the Great War which had been published a few years after the First World War ended, had not matched the standard set by the Official History of Australia in the War of 1914–1918, edited by Charles Bean. In 1940, with a view to the production of an official history of New Zealand's contributions to the Second World War, an archivist was appointed to the headquarters of the 2nd New Zealand Expeditionary Force (2NZEF) to ensure the preservation of important documentation and records. He was joined by Eric McCormick, a published literary and art historian, in 1941. After he became aware of the progress made on the Australian official history, McCormick pushed for progress on New Zealand's own efforts in this regard. By 1944, the New Zealand government had decided to appoint an Official Historian who would be Editor-in-Chief of an official history which would not only cover the military contribution to the war effort, but also the efforts of the New Zealand people.