64th Regiment or 64th Infantry Regiment may refer to:
- Loudon's Highlanders, a unit of the British Army raised in 1745 and ranked as 64th Foot
- 64th (2nd Staffordshire) Regiment of Foot, a unit of the British Army
- 64th (Liverpool Irish) Lancashire Rifle Volunteer Corps, a unit of the British Territorial Army
- 64th (Queen's Own Royal Glasgow Yeomanry) Anti-Tank Regiment, Royal Artillery, British Yeomanry unit
- 64th Armor Regiment, a unit of the US Army
- 64th Infantry Regiment (United States), a unit of the US Army
- American Civil War
- Union (Northern) Army
- 64th Illinois Volunteer Infantry Regiment
- 64th New York Volunteer Infantry Regiment
- 64th Ohio Infantry
- 64th United States Colored Infantry Regiment
- Confederate (Southern) Army