Who is the youngest ever Nobel Prize laureate in Physics?

Sir William Lawrence Bragg was an Australian-born British physicist and X-ray crystallographer, discoverer of Bragg's law of X-ray diffraction, which is basic for the determination of crystal structure. Bragg was, until October 2014, the youngest ever Nobel laureate; he won the prize in 1915 at the age of 25. He remains the youngest recipient of the Physics Prize.