84th Regiment

84th Regiment or 84th Infantry Regiment may refer to:


 * 84th Regiment of Foot (1759), a unit of the United Kingdom Army, active from 1759–1765, which served entirely in British India
 * 84th Infantry Regiment (Philippine Commonwealth Army), a unit of the Philippine Commonwealth Army, active from 1942–1946, which served in the Second World War
 * 84th Regiment of Foot (Royal Highland Emigrants), a unit of the United Kingdom Army, active from 1775–1784, which served in the American Revolution
 * 84th (York and Lancaster) Regiment of Foot, a unit of the United Kingdom Army, active from 1793–1881, which served in the Napoleonic Wars and in India
 * 84th Illinois Volunteer Infantry Regiment, a unit of the Union (North) Army during the American Civil War
 * 84th Regiment Indiana Infantry, a unit of the Union (North) Army during the American Civil War