Johan Peter Holtsmark (13 February 1894 – 10 December 1975) was a Norwegian physicist, who studied spectral line broadening and electron scattering.

[1][2][3] Together with the Swedish physicist Hilding Faxén published Holtsmark a work in 1927 about scattering of electrons in gases.

[citation needed] Between 1934 and 1937 he led the construction of a Van de Graaff accelerator at the Norwegian Institute of Technology, which became the first particle accelerator to go into operation in Scandinavia.

[5] Holtsmark was one of the founding fathers of CERN and represented Norway to the European Council for Nuclear Research,[6] which later led into the establishment of the organization itself.

He was awarded the Fridtjof Nansen Excellent Research Award in 1969, was a fellow of the Norwegian Academy of Science and Letters from 1925 and the Royal Norwegian Society of Sciences and Letters from 1926.