Boris Yakovlevich Podolsky (Russian: Бори́с Я́ковлевич Подо́льский; June 29, 1896 – November 28, 1966) was a Russian-American physicist of Jewish descent, noted for his work with Albert Einstein and Nathan Rosen on entangled wave functions and the EPR paradox.

After receiving a Bachelor of Science degree in electrical engineering from the University of Southern California in 1918, he served in the US Army and then worked at the Los Angeles Bureau of Power and Light.

In a letter dated November 10, 1933, to Abraham Flexner, founding director of the Institute for Advanced Study at Princeton, Einstein described Podolsky as "one of the most brilliant of the younger men who has worked and published with [Paul] Dirac."

A 2009 book by John Earl Haynes, Harvey Klehr and Alexander Vassiliev, Spies: The Rise and Fall of the KGB in America, identifies Podolsky as a contact (QUANTUM) who met twice with Soviet secret services in 1942 and 1943.

Early during World War II, several VENONA cables identify a contact named QUANTUM who sought out Soviet intelligence in 1942 and asked for a position in the USSR to work on processing Uranium 235.