Boris Nikolaevich Yuzhin (Russian: Борис Николаевич Южин; born February 21, 1942) is a former Soviet spy. He was a mole in the KGB, spying for the Federal Bureau of Investigation in the 1970s and 1980s before being caught and imprisoned. Arriving in San Francisco in 1975, he, as an expert in semiconductors, posed as a visiting scientist at UC Berkeley where he attempted to find any useful information or possible contacts. During his second assignment to the United States, Yuzhin was assigned by the KGB to monitor student activities under the cover of a Tass correspondent.