13th Regiment

• 13 Squadron (disambiguation)
• 13th Army (Soviet Union)
• 13th Battalion (disambiguation)
• 13th Brigade (disambiguation)
• 13th Cavalry Regiment (United States)
• 13th Continental Regiment
• 13th Division (disambiguation)
• 13th Group (disambiguation)
• 13th Illinois Volunteer Infantry Regiment
• 13th Infantry Regiment (Greece)
• 13th Infantry Regiment (Imperial Japanese Army)
• 13th Infantry Regiment (United States)
• 13th Iowa Volunteer Infantry Regiment
• 13th Maine Volunteer Infantry Regiment
• 13th Massachusetts Regiment
• 13th Michigan Volunteer Infantry Regiment
• 13th Parachute Dragoon Regiment
• 13th Pennsylvania Regiment
• 13th Regiment Illinois Volunteer Cavalry
• 13th Regiment Massachusetts Volunteer Infantry
• 13th Virginia Regiment
• 13th West Virginia Volunteer Infantry Regiment
• 13th Wisconsin Volunteer Infantry Regiment
• Somerset Light Infantry