33rd Regiment
- 33 (Lancashire and Cheshire) Signal Regiment
- 33 Combat Engineer Regiment
- 33 Engineer Regiment (EOD)
- 33 Signal Regiment (Canada)
- 33 Squadron (disambiguation)
- 33rd (St Pancras) Searchlight Regiment, Royal Artillery
- 33rd Arkansas Infantry Regiment
- 33rd Brigade (disambiguation)
- 33rd Division (disambiguation)
- 33rd Field Artillery Regiment
- 33rd Illinois Volunteer Infantry Regiment
- 33rd Indiana Infantry Regiment
- 33rd Infantry Regiment (United States)
- 33rd Iowa Volunteer Infantry Regiment
- 33rd Light Dragoons
- 33rd New York Volunteer Infantry Regiment
- 33rd Ohio Infantry
- 33rd Pennsylvania Infantry
- 33rd Punjabis
- 33rd Regiment (3rd Burma Bn.) Madras Infantry
- 33rd Regiment (Vietnam People's Army)
- 33rd Regiment Alabama Infantry
- 33rd Regiment Kentucky Volunteer Infantry
- 33rd Regiment of Foot
- 33rd Tennessee Infantry Regiment
- 33rd United States Colored Infantry Regiment
- 33rd Virginia Infantry
- 33rd Wisconsin Volunteer Infantry Regiment