Sir William Lawrence Bragg (31 March 1890 – 1 July 1971) was an Australian-born British physicist who shared the 1915 Nobel Prize in Physics with his father William Henry Bragg "for their services in the analysis of crystal structure by means of X-rays", an important step in the development of X-ray crystallography.
As of 2024, he is the youngest ever Nobel laureate in physics, or in any science category, having received the award at the age of 25. Bragg was the director of the Cavendish Laboratory, Cambridge, when the discovery of the structure of DNA was reported by James D. Watson and Francis Crick in February 1953.