William Lawrence Bragg was the son of William Henry Bragg. Born in Adelaide, Australia, he was educated at the university there and at Cambridge University, where he became a fellow and lecturer. After the war, in 1919, he was appointed professor of physics at Manchester University. He succeeded Ernest Rutherford in 1938, after a short period in 1937 as director of the National Physical Laboratory, as head of the Cavendish Laboratory and Cavendish Professor at Cambridge. Finally, in 1953, he became director of the Royal Institution, London, a post his father had held previously and which he held until his retirement in 1961.

Success came very early to Bragg, who shared the Nobel Prize for physics with his father in 1915. Following Max von Laue's discovery of x-ray diffraction by crystals in 1912, Lawrence Bragg in the same year formulated what is now known as the Bragg law:

nλ = 2dsinθ

which relates the wavelength of x-rays (λ), the angle of incidence on a crystal θ, and the spacing of crystal planes d, for x-ray diffraction. n is an integer (1, 2, 3, etc.).

Bragg collaborated with his father in working out the crystal structures of a number of substances. Early in this work they showed that sodium chloride does not have individual molecules in the solid, but is an array of sodium and chloride ions. In 1915 the Braggs published their book X-rays and Crystal Structure.

Lawrence Bragg later worked on silicates and on metallurgy. He was responsible for setting up a program for structure determinations of proteins.