Thirty-First Army (Japan)
| Japanese Thirty First Army | |
|---|---|
Japanese POWs at Guam at time of the surrender of Japan | |
| Active | February 18, 1944 - August 15, 1945 |
| Country | Empire of Japan |
| Branch | Imperial Japanese Army |
| Type | Infantry |
| Role | Corps |
| Garrison/HQ | Truk |
| Engagements | Operation Hailstone Battle of Saipan Battle of Guam |
The Japanese 31st Army (第31軍, Dai-sanjyū-ichi gun) was an army of the Imperial Japanese Army during World War II.