Pierre-Louis Moreau de Maupertuis (Saint-Malo, July 17, 1698 – Basel, July 27, 1759) is a French mathematician, philosopher and man of letters.

He becomes the Director of the Académie des Sciences, and the first President of the Prussian Academy of Science, at the invitation of Frederick the Great.

Maupertuis makes an expedition to Lapland to determine the shape of the earth.

He is often credited with having invented the principle of least action; a version is known as Maupertuis' principle – an integral equation that determines the path followed by a physical system.

His work in natural history has its interesting points, since he touches on aspects of heredity and the struggle for life.