The 113th Heavy Anti-Aircraft Regiment (113th HAA Rgt) was an air defence unit of the British Army's Royal Artillery during World War II. It saw action during The Blitz, landed in Normandy on D-Day and served throughout the subsequent campaign in North West Europe, operating as medium artillery in the Battle of the Scheldt, Unusually, its AA guns were successfully used to destroy enemy submarines in the closing stages of the war.