Sergey Dmitrievich Poltoratsky (1803, 1884) was a well-known Russian bibliophile and bibliographer from the Poltoratsky family. He received his early education at home under the guidance of his father, D. M. Poltoratsky. In 1818 and 1820, Sergey studied at the Richelieu Lyceum, after which he entered the Moscow School of Coachmen, graduating in 1823 with the rank of officer. However, his military career was short-lived: in 1827, he retired and settled in the family estate 'Avchurino', fully dedicating himself to bibliographic research. His love for books was inherited from his maternal grandfather, P. K. Khlebnikov, who left him a rich library, which was later significantly expanded.

It is known that in 1826 and 1828, Poltoratsky maintained close relations with Alexander Pushkin. During this time, he actively collaborated with the 'Moscow Telegraph' and often met with the poet. Pushkin mentioned Poltoratsky in his letters as a card-playing partner. On a copy of 'Poltava', published in 1829, Pushkin left an inscription: 'To Poltoratsky from Pushkin. April 2, 1829. Moscow.'

Poltoratsky published articles on literature in Russian and foreign publications, but his main works were dedicated to the study of the first Russian newspapers. He collected an extensive collection of early Russian periodicals, part of which was gifted to him by Pushkin on April 29, 1836.

In 1830, Poltoratsky went abroad and, after participating in the July Revolution, lived for a long time as a semi-emigrant, returning to Russia only in 1832.

His significant work, 'Dictionary of Russian Writers', remained unpublished, except for some fragments released under the title 'Materials for the Dictionary of Russian Writers'.

In 1856, due to financial difficulties, Poltoratsky was forced to sell his library, part of which ended up in the Rumyantsev Museum. In 1868, finding himself in dire straits, he moved with his family to Charlottenburg (Prussia), and then to France, settling in Neuilly, a suburb of Paris, where he passed away. He spent the last years of his life traveling between France and England.