Alexis Guignard, comte de Saint-Priest (27 April 1805 in Saint Petersburg – 29 September 1851 in Moscow) was a French diplomat, historian, and Peer of France.

He was the eleventh member elected to occupy seat 4 of the Académie française in 1849.

Guignard was the son of an émigré French nobleman Armand Charles Emmanuel Guignard, comte de Saint-Priest (1782–1863) and his Russian wife, Princess Sophie Galitzine.

His grandfather, François-Emmanuel Guignard, comte de Saint-Priest, was one of the last ministers of Louis XVI of France.

During the July Monarchy, he departed from the Legitimist tradition of his family, particularly that of his uncle Emmanuel Louis Marie de Guignard, vicomte de Saint Priest, to become a warm friend to King Louis-Philippe of France, whom he served between 1833 and 1838 as an ambassador in Brazil, Portugal and Denmark.