Anatoly Sergeevich Chernyaev (May 25, 1921, in Moscow – March 13, 2017 in Moscow) was a Russian historian and writer who was a principal foreign-policy advisor to General Secretary Mikhail Gorbachev during the final days of the Soviet Union.

After fighting in World War II, Chernyaev studied history at Moscow State University, where he would teach contemporary history from 1950 to 1958. In 1961, he joined the International Department of the Central Committee of the Communist Party of the Soviet Union, where he became a senior analyst. He became General Secretary Gorbachev's foreign-policy advisor in 1986 and continued to advise Gorbachev when the latter became President of the Soviet Union.

In 2004, Chernyaev donated his diaries from the Gorbachev period to the National Security Archive at George Washington University, which has published portions of them in English translation; according to the editor, "One can confidently say that every bold foreign policy initiative advanced by Gorbachev in the years 1986-1991 bears Chernyaev's mark on it."

Since then, the National Security Archive has made available Chernyaev's diaries for the years 1972 and 1973. Diaries from 1974 to 1985 will also be made available in due course.