The 21st Battalion, was an infantry battalion of the New Zealand Military Forces, which served during the Second World War. Formed in November 1939, it was part of the 5th Brigade, 2nd Division of the 2nd New Zealand Expeditionary Force. The battalion saw action in Greece, Crete, North Africa and Italy.
- Cody, Joseph (1953). 21 Battalion. The Official History of New Zealand in the Second World War 1939–1945 VI. Wellington, New Zealand: Historical Publications Branch. OCLC 11136356.