45th Regiment

45th Regiment or 45th Infantry Regiment may refer to:

• 45th Detached Reconnaissance Regiment, a special forces unit of the Russian Army
• 45th (Leeds Rifles) Royal Tank Regiment, a unit of the United Kingdom Army
• 45th (Nottinghamshire) Regiment of Foot, a unit of the United Kingdom Army
• 45th Infantry Regiment (United States), a unit of the United States Army

American Civil War regiments 

Union (Northern) Army regiments

• 45th Illinois Volunteer Infantry Regiment
• 45th Iowa Volunteer Infantry Regiment
• 45th Wisconsin Volunteer Infantry Regiment

See also

• 45th Division (disambiguation)
• 45th Brigade (disambiguation)
• 45th Squadron (disambiguation)