Konstantin Georgiyevich Preobrazhenskiy (Russian: Константин Георгиевич Преображенский; born 1953 in Moscow) is a former KGB lieutenant colonel, an intelligence expert and the author of several books and numerous articles about Russian secret police organizations.
Preobrazhenskiy is known for his publications about KGB operations in Japan, recruitment of Russian emigrants by Russian Foreign Intelligence Service, and infiltration of the Russian Orthodox Church by the KGB/Federal Security Service (FSB).