Platonov was born in the city of Chernigov, Russian Empire and attended a private gymnasium in St. Petersburg until 1878, when he went to the Department of History and Philology of St. Petersburg University until 1882. He was a student of Konstantin Bestuzhev-Ryumin, who recommended that he be given the opportunity to "prepare to be a professor."

Platonov belonged to the "St. Petersburg school" of Russian historiography, which paid special attention to the study and publication of historical sources. Platonov gained his master's thesis in 1888 writing about Old Russian Legends and Tales About the Seventeenth-Century Time of Troubles as a Historical Source for which he gained the Uvarov Award of the Academy of Sciences.

Platonov's scholarly career was centered on the University of St Petersburg, where he was held in highest repute for his detailed studies of the Time of Troubles (1923) and Oprichnina. Platonov's history textbooks, impeccably written and easily readable, enjoyed such popularity that he was asked by the tsar to teach history to his children. In 1909, he was admitted to the Russian Academy of Sciences.

Unlike some of his disciples (such as Alexander Presnyakov), Platonov did not change his views after the Revolution and stood aloof from the mainstream Marxist historiography, as represented by Mikhail Pokrovsky. Nevertheless, he was permitted to administer the Archaeographic Commission in 1918-29, the Pushkin House (i.e., the Russian Literature Institute) in 1925–1929 and the Academy's Library in 1925–1928.

On 12 January 1930 Platonov was accused of taking part in a royalist conspiracy, arrested and exiled to Samara, where he died three years later on January 10, 1933.^[1] However, a number of his historical works continued to be reprinted later in the decade, and in 1967 he was formally rehabilitated.

• History of Russia (1925), New York, Macmillan.
• The Time of Troubles: A Historical Study of the Internal Crises and Social Struggle in Sixteenth- and Seventeenth-Century Muscovy (1970), Lawrence, University Press of Kansas.
• Moscow and the West, (1972), Hattiesburg, Academic International.
• Boris Godunov, Tsar of Russia, (1973) with an introductory essay. Gulf Breeze, Florida, Academic International Press (includes 'S.F. Platonov: Eminence and Obscurity' an introductory essay by John T. Alexander
• Ivan the Terrible, (1974), Gulf Breeze, Florida, Academic International Press.

• St Petersburg Encyclopedia accessed 13 July 2008
• Russian History Encyclopedia: Sergei Fyodorovich Platonov accessed 17 July 2008
• 'Sergei Fedorovich Platonov (1860 - 1933): A Life for Russia.' by Aleksei Nikolaevich Tsamutali published in Historiography of Imperial Russia, ed. Tomas Sanders, (1999) Armonk, New York, M.E. Sharpe.

• Works by or about Sergey Platonov at Internet Archive