On 18 September 1939, Švenčionys was occupied by the Red Army and, on 14 November 1939, incorporated into the Byelorussian SSR. The Soviets placed it firstly in part of Vileyka Oblast of the Belorussian SSR in 1939 but then incorporated into the Lithuanian SSR on 25 November 1940. Švenčionys was occupied by the German Army from 27 June 1941 until 7 July 1944 and placed under the administration of the Generalbezirk Litauen of Reichskommissariat Ostland. In 1942 the Lithuanian Security Police murdered several hundreds of Poles in the village. Most of the municipal area remained part of the Lithuanian SSR except the Ashmyany region which was reincorporated into Belarus in 1944.