Pierre Louis Maupertuis, French mathematician and philosopher (d. 1759)

Pierre Louis Moreau de Maupertuis (; French: [mopɛʁtɥi]; 1698 – 27 July 1759) was a French mathematician, philosopher and man of letters. He became 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 made 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's principle – an integral equation that determines the path followed by a physical system. His work in natural history is interesting in relation to modern science, since he touched on aspects of heredity and the struggle for life.