Pierre-Gilles de Gennes (born October 24, 1932) is a French physicist and Nobel laureate.

He was born in Paris, France and was home-schooled to the age of 12. Later, Gennes studied at the École Normale Supérieure. After leaving the École in 1955, he became a research engineer at the Saclay center of the Commissariat à l'Énergie Atomique, working mainly on neutron scattering and magnetism, with advice from A. Abragam and J. Friedel. He defended his Ph.D. in 1957.

In 1959, he was a postdoctoral visitor with C. Kittel at the University of California at Berkeley, and then spent 27 months in the French Navy. In 1961, he was assistant professor in Orsay and soon started the Orsay group on supraconductors. In 1968, he switched to studying liquid crystals.

In 1971, he became professor at the Collège de France, and participated to STRASCOL (a joint action of Strasbourg, Saclay and Collège de France) on polymer physics. From 1980 on, he became interested in interfacial problems : the dynamics of wetting and adhesion.

In 1991, he received the Nobel Prize in physics. He was then director of the École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris.

More recently, he worked on granular materials.