Nikolai Mezentsov

Nikolay Vladimirovich Mezentsov (Russian: Николай Владимирович Мезенцов; April 4(23) (OS/NS), 1827 – August 4(16) (OS/NS), 1878) was a Russian statesman, adjutant general (1871), and member of the State Council of Imperial Russia (1877).

Mezentsov began his military career in 1845. He participated in the Crimean War of 1853-1856. In 1864, he was appointed Chief of Staff of the Gendarmery Corps; in 1874, Deputy Chief of Gendarmery; and finally, in 1876, Chief of Gendarmery and Chief of the "Third Department" (Третье отделение; Political Surveillance and Investigations Department) of His Imperial Highness's Personal Chancellery.

Mezentsov was assassinated in 1878 by Sergey Kravchinsky.