Aleksandr Il'ich Leipunskii (December 7, 1903 – August 14, 1972) was a Polish-born Jewish physicist. He was born in the small village of Dragli, Russian Poland. In 1921, he entered the Leningrad Polytechnic Institute, graduating in 1926. He then joined the Leningrad Physico-Technical Institute, where he studied atomic interactions with electrons and molecules. In 1930, he began research into nuclear physics. He helped organize the Ukrainian Physics and Technology Institute in Kharkiv and became its director. In 1934, he was sent to England for a year as a visiting researcher at the Rutherford Laboratory. In September 1937 Leipunskii was arrested as a German spy in connection with the UPTI Affair, but later released.