Pierre Courtade was a French writer and journalist.

Pierre Courthion was a Swiss art critic and historian known for his work on American and French art.

Pierre Coustillas was a French literary scholar and emeritus professor of English at the University of Lille. He was a specialist in the work of George Gissing.

Pierre d'Ailly was a French theologian, astrologer and cardinal of the Roman Catholic Church.

Pierre Daniel Huet was a French churchman and scholar, editor of the Delphin Classics, founder of the Académie de Physique in Caen (1662-1672) and Bishop of Soissons from 1685 to 1689 and afterwards of Avranches.

Pierre Daninos was a French writer and humorist.

Pierre de Boissat was a soldier, writer, poet and translator.

Pierre de Bourdeille, called the seigneur et abbé de Brantôme, was a French historian, soldier and biographer.

Pierre de Fermat was a French mathematician who is given credit for early developments that led to infinitesimal calculus, including his technique of adequality. In particular, he is recognized for his discovery of an original method of finding the greatest and the smallest ordinates of curved lines, which is analogous to that of differential calculus, then unknown, and his research into number theory. He made notable contributions to analytic geometry, probability, and optics. He is best known for his Fermat's principle for light propagation and his Fermat's Last Theorem in number theory, which he described in a note at the margin of a copy of Diophantus' Arithmetica. He was also a lawyer at the Parlement of Toulouse, France.

Pierre de L'Estoile was a French diarist and collector.