George Kisevalter (4 April 1910 – October 1997) was a CIA operations officer who handled both Major Pyotr Popov, the first Soviet GRU officer run by the CIA, and Colonel Oleg Penkovsky.
George Kisevalter was born in St. Petersburg, Russia, the son of a Russian Army munitions expert and grandson of a Russian deputy finance minister. In 1915, the elder Kisevalter, accompanied by his family, was sent to the United States in order to purchase weapons for the Tsar. The Bolshevik Revolution forced the Kisevalters to remain in the United States, where they eventually took US citizenship.
The Kisevalters settled in New York City, where the young George attended Stuyvesant High School. In 1926, he entered Dartmouth College to study engineering. Among his classmates was Nelson Rockefeller.
Kisevalter spent much of World War II as an army officer involved in supporting the Soviet war effort through the Lend-Lease Program. His first experience with intelligence came in 1944 when, as a fluent Russian speaker, he was assigned to military intelligence in order to work on Soviet intelligence projects. Because of his growing expertise in Soviet matters, as well as his German language skill, Kisevalter was one of the officers who interviewed Major General Reinhard Gehlen, after the latter's surrender to the US military. Gehlen had been the German chief of intelligence for the eastern front, and was well versed in Soviet military and political affairs.
Kisevalter had a brief civilian career before joining the CIA. By 1953, he was a branch chief in the Soviet Division of the Directorate of Operations. Also in 1953, a major of the GRU named Pyotr Semyonovich Popov contacted American intelligence in Vienna and offered to spy for the United States. Kisevalter was selected as Popov's handler. Based in Vienna, Austria, Kisevalter spent the next five years handling Popov, who provided the United States with detailed information on Soviet military plans and capabilities. During the period when he spied for the United States, Popov was considered to be "the CIA's most important agent." Kisevalter's involvement came to an end with Popov's capture and subsequent execution in 1959.