66th Regiment

66th Regiment may refer to:


 * 66th (Berkshire) Regiment of Foot, an infantry unit of the British Army
 * 66th (Leeds Rifles) (West Yorkshire Regiment) Heavy Anti-Aircraft Regiment, Royal Artillery, British Army
 * 66th Punjabis, a unit of the British Indian Army
 * 66th Infantry Regiment (United States), a unit of the United States Army
 * 66th Armor Regiment, an armoured unit of the US Army
 * 66th Armoured Regiment (India), an armoured unit of the Indian Army
 * 66th Infantry Regiment (Imperial Japanese Army), a unit of the Imperial Japanese Army


 * American Civil War regiments
 * 66th Indiana Infantry Regiment, Union Army
 * 66th Illinois Volunteer Infantry Regiment, Union Army
 * 66th New York Volunteer Infantry, Union Army
 * 66th Ohio Infantry, Union Army