31 Squadron or 31st Squadron may refer to:
- No. 31 Squadron RAAF, Royal Australian Air Force
- 31st Squadron (Belgium), Belgian Air Force
- No. 31 Squadron (Finland)
- No. 31 Squadron RAF, United Kingdom Royal Air Force
- 31st Training Squadron (JASDF), Japanese Air Self-Defense Force
- 31st Airlift Squadron, United States Air Force
- 31st Combat Communications Squadron, United States Air Force
- 31st Rescue Squadron, United States Air Force
- 31st Reconnaissance Squadron (disambiguation), several units of the United States Air Force
- 31st Tactical Training Squadron, United States Air Force
- 31st Test and Evaluation Squadron, United States Air Force
- VFA-31 (Strike Fighter Squadron 31), United States Navy
- Marine Aviation Logistics Squadron 31, United States Marine Corps
See also