Count Pyotr Andreyevich Tolstoy (1645 - 1729) was a Russian statesman prominent during and after the reign of Peter the Great. He was the ancestor of all the Counts Tolstoy, including the novelist Leo Tolstoy.

Pyotr Tolstoy served in 1682 as chamberlain at the court of Feodor III. On account of his family relationship with the Miloslavsky family, he miscalculated the strength of the tsarevna Sophia Alekseyevna and became one of her most energetic supporters, but contrived to join the other, and winning, side just before the final catastrophe. For a long time Peter kept his latest recruit at arm's length; but when, in 1697, Tolstoy volunteered to go to Venice to learn Italian and ship-building, Peter could not resist the subtle flattery implied in such a proposal from a middle-aged Muscovite noble.

In November of 1701, Tolstoy was appointed the first regularly accredited Russian ambassador to the Porte, and more than justified the confidence of the most exacting of masters. Even before Poltava, Tolstoy had the greatest difficulty in preventing the Turks from aiding the Swedes, and when Charles XII took refuge on Turkish soil he instantly demanded his extradition. This was a diplomatic blunder, as it only irritated the already alarmed Turks; and on October 10, 1710 Tolstoy was thrown into the Seven Towers, a proceeding tantamount to a declaration of war against Russia. On his release from this Turkish hell, in 1714, he returned to Russia, was created a senator, and closely associated himself with the omnipotent favorite, Menshikov.

In 1717, his position during Peter's reign was secured once for all by his successful mission to Naples to bring back the unfortunate tsarevich Alexius, whom he may be said to have literally hunted to death. For this he earned the undying hatred of the majority of the Russian people; but Peter naturally regarded it as an inestimable service and loaded Tolstoy with honors and riches, appointing him, moreover, the head of the Secret Chancellery (Тайная канцелярия), or official torture chamber, a post for which Tolstoy was by nature eminently fitted. He materially assisted Menshikov to raise the empress consort to the throne on the decease of Peter in 1725, and the new sovereign made him a count and one of the six members of the newly instituted Supreme Privy Council (Верховный тайный совет).

Tolstoy was well aware that the elevation of the grand duke Peter II, son of the tsarevich Alexius, would put an end to his own career and endanger his whole family, so that when Menshikov, during the last days of Catherine I, declared in favor of Peter, Tolstoy endeavoured to form a party of his own whose object it was to promote the accession of Catherine's second daughter, the tsarevna Elizabeth. But Menshikov was too strong and too quick for his ancient colleague. On the very day of the empresss death (May 11, 1727), Tolstoy, now in his eighty-second year, was banished to the Solovetsky Monastery in the White Sea, where he died two years later.

Pyotr Tolstoy is the author of a sketch of the impressions made upon him by Western Europe during his tour in the years 1697 - 1698 and also of a detailed description of the Black Sea.