Mark Zborowski also Mark Zborovsky, (d. 1990) is considered among the most fearsome of Soviet terrorist operatives of all time.  Zborowski was implicated in several assassinations in 1936 and 1937. As a medical researcher, Zborowski murdered a dissident with a poisoned orange at the Soviet‑run hospital in Paris. In the 1940s Zborowski worked for the KGB.
In the Venona project Zborowski was identified as "Tulip" and "Kant" in Venona decrypted cables after September 1944.
In the 1960s Zborowski worked as a medical researcher in San Francisco and trained numerous psychiatrists and medical specialists in the Bay Area.
- Christopher M. Andrew and Vasili Mitrokhin, The Sword and the Shield: The Mitrokhin Archive and the Secret History of the KGB (New York: Basic Books, 1999).
- The Strange Case of Doctor Zborowski and Monsieur Etienne, by Philippe Videlier, in Le Monde Diplomatique, Dec. 1992.