49th Regiment
- 49th (Princess Charlotte of Wales's) (Hertfordshire) Regiment of Foot
- 49th Brigade (disambiguation)
- 49th Division (disambiguation)
- 49th Field Artillery Regiment (United States)
- 49th Field Artillery Regiment, RCA
- 49th Hutsul Rifle Regiment
- 49th Illinois Volunteer Infantry Regiment
- 49th Indiana Infantry Regiment
- 49th Infantry Regiment (United States)
- 49th New York Volunteer Infantry
- 49th North Carolina Infantry
- 49th Ohio Infantry
- 49th Pennsylvania Infantry
- 49th Regiment Kentucky Volunteer Mounted Infantry
- 49th Regiment of Bengal Native Infantry
- 49th Royal Tank Regiment
- 49th Squadron (disambiguation)
- 49th Virginia Infantry
- 49th Wisconsin Volunteer Infantry Regiment
- The Hastings and Prince Edward Regiment