Stepan Dmitrievich Nechayev was a Russian historian, amateur archaeologist, and official who held the position of senator and actual secret advisor. From 1833 to 1836, he served as the chief prosecutor of the Holy Synod. He was the son of the wealthy landowner Dmitry Stepanovich Nechayev and Anna Ivanovna Sivers. His sister, Feodosia Dmitrievna, was married to S. P. Zhikharev. Nechayev's father, the leader of the nobility of Dankov district, owned the estate Polibino.

Stepan Dmitrievich received a home education and, after passing exams for Moscow University, entered the service in the Collegium of Foreign Affairs in 1811. Three months later, he transferred to the office of the military governor of Riga, Prince Y. I. Lobanov-Rostovsky, where he remained until December 1812.

In 1814, Nechayev became the honorary supervisor of the Skopin school, and in 1817 and 1823, he headed the schools of Tula province and the Tula gymnasium. In Tula, he opened a Lancaster school, four boarding houses, and several other educational institutions. Working with Prince D. V. Golitsyn, Nechayev actively participated in the activities of charitable institutions in Moscow.

In 1826, he was sent to assist Count A. G. Stroganov in investigating the schism in Perm province. In 1827, he was enrolled in His Majesty's Own Chancellery. With the support of Prince A. N. Golitsyn and his wife's uncle, Prince P. S. Meshchersky, Nechayev took up the post of chief prosecutor of the Synod in December 1828, and in April of the following year, he became a member of the Collegium of Spiritual Schools. During this period, he became close to Metropolitan Philaret of Moscow.

In December 1831, Nechayev received the rank of actual state councilor, and in April 1833, he became the chief prosecutor of the Synod, holding this position until June 1836. During his tenure, the synodal archive was organized, and control over the financial resources of the spiritual department was introduced. He also organized secret gendarmerie oversight in some dioceses.

Since 1828, Stepan Dmitrievich was married to Sofia Sergeyevna Maltseva, the daughter of cornet Sergey Akimovich Maltsev. She passed away in 1836 in Crimea from tuberculosis, leaving two sons and two daughters.

In his youth, Nechayev was passionate about literature and published articles in the "Herald of Europe" by N. M. Karamzin, of which he was a member of the historical circle. He wrote about the Battle of Kulikovo and the discoveries of ancient weapons on his lands, suggesting that the legendary Kulikovo Field was located there. He organized the installation of a memorial column and began fundraising for the Church of Sergius of Radonezh. In his estate Polibino, Nechayev housed a collection of antiques related to the Battle of Kulikovo.

Stepan Dmitrievich died in 1860 in the village of Storozhevaya Sloboda in Ryazan province and was buried next to his wife in the Novodevichy Monastery in Moscow. The gravestones of the couple were destroyed in the 1930s during a campaign to eliminate urban cemeteries and recycle stone monuments.