89th Regiment of 89th Infantry Regiment may refer to:

89th Cavalry Regiment, a unit of the United States Army 89th Regiment of Foot (disambiguation), several units of the British Army 89th (Cinque Ports) Heavy Anti-Aircraft Regiment, Royal Artillery 89th Punjabis, a unit of the British Indian Army

American Civil War regiments: 89th Illinois Infantry Regiment, a unit of the Union Army 89th Indiana Infantry Regiment, a unit of the Union Army

See also 89th Division (disambiguation)