Percy Williams Bridgman (April 21, 1882–August 20, 1961) was an American physicist who won the 1946 Nobel Prize in Physics for his work on the physics of high pressures.

Bridgman was born in Cambridge, Massachusetts. He entered Harvard University in 1900, studying physics, and from 1910 he began teaching at Harvard, finally as a professor from 1919. He had, in 1905, begun undertaking research regarding certain phenomena under the influence of pressure. Due to a machinery malfunction, he modified his pressure apparatus, and the result was that he had invented a new piece of machinery that would enable him to create pressures up to and above 100,000 kg/cm². This is a huge improvement on previous machinery in which pressures of only 3000 kg/cm² could be attained. He developed the Bridgman seal.

With this new apparatus a plethora of new research was investigated, including research into the effect of pressure on electrical resistance, and solid and fluid conditions under pressure.

Brigman is known also for his studies of electrical conduction in metals and properties of crystals and for his writings on the philosophy of modern science.