Philipp Eduard Anton von Lenard (7 June 1862 – 20 May 1947) was a Hungarian-born German physicist. He won the Nobel Prize for Physics in 1905 for his work on cathode rays. His most important work was his study of the photoelectric effect. He discovered that the energy (speed) of the electrons from a cathode depends on the wavelength, not the intensity of the light.
Lenard was a nationalist and anti-Semite. He was a supporter of Adolf Hitler in the 1920s. He was a role model for the "Deutsche Physik" movement during the Nazi period. He said that Albert Einstein's contributions to science were "Jewish physics".