Pierre-Simon Ballanche was a French writer and counterrevolutionary philosopher, who elaborated a theology of progress that possessed considerable influence in French literary circles in the beginning of the nineteenth century. He was the ninth member elected to occupy seat 4 of the Académie française in 1842.

Pierre-Simon, Marquis de Laplace was a French scholar and polymath whose work was important to the development of engineering, mathematics, statistics, physics, astronomy, and philosophy. He summarized and extended the work of his predecessors in his five-volume Mécanique céleste (1799–1825). This work translated the geometric study of classical mechanics to one based on calculus, opening up a broader range of problems. In statistics, the Bayesian interpretation of probability was developed mainly by Laplace.

Piers Anthony Dillingham Jacob is an American author in the science fiction and fantasy genres, publishing under the name Piers Anthony. He is best known for his long-running novel series set in the fictional realm of Xanth.

Piers Brendon is a British historian and writer, known for historical and biographical works.

Piers Paul Read FRSL is a British novelist, historian and biographer. He was first noted in 1974 for a book of reportage, Alive: The Story of the Andes Survivors, later adapted as a feature film and a documentary. Read was educated at St. John's College, Cambridge, where he studied history.

Piers Torday is a British children's writer. The son of the novelist Paul Torday, he was born in Northumberland and was a theatre and television producer for many years.

François Haverschmidt, also written as HaverSchmidt, was a Dutch minister and writer, who wrote prose under his own name but remains best known for the poetry published under the pen name of Piet Paaltjens.

Pieter Anton Tiele was for many years the librarian of Utrecht University.

Pieter Aspe was a Belgian writer of a series of detective stories starring inspector Pieter Van In. These were adapted for the long-running TV series Aspe (2004–14) starring Herbert Flack. He died at the age of 68 years.

Pieter Boddaert (Dutch pronunciation: [ˈpitər ˈbɔdaːrt]; 1730 – 6 May 1795) was a Dutch physician and naturalist.