William Lawrence Bragg, Australian-English physicist and academic, Nobel Prize laureate (died 1971)

Sir William Lawrence Bragg 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.

The Nobel Prize in Physics is an annual award given by the Royal Swedish Academy of Sciences for those who have made the most outstanding contributions to mankind in the field of physics. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895 and awarded since 1901, the others being the Nobel Prize in Chemistry, Nobel Prize in Literature, Nobel Peace Prize, and Nobel Prize in Physiology or Medicine. Physics is traditionally the first award presented in the Nobel Prize ceremony.