Wolfgang Pauli was an Austrian-American physicist noted for his work on quantum mechanics.

Shortly after completing his Ph.D. in 1921 at the Ludwig-Maximilian University in Munich, Pauli published a review  the theory of relativity for the Encyklopaedie der mathematischen Wissenschaften (a German "Encyclopedia of Mathematical Sciences") that was praised by Einstein.  In 1922 Neils Bohr invited Pauli to join Bohr's Institute in Copenhagen.

In 1924, Pauli proposed a new quantum degree of freedom to resolve inconsistencies between observed molecular spectra and the developing theory of quantum mechanics. He formulated the Pauli exclusion principle in 1925, perhaps his most important work, which stated that no two electrons could exist in the same quantum state. He was the first to recognize the existence of the neutrino, an uncharged and mass-less particle that carries off energy in radioactive-disintegration.

Less than a year after this Heisenberg submitted his article on quantum mechanics which was to change the whole approach to the topic. Pauli, who before that had begun to feel that further advances could not be made with the theory as it then existed, quickly made progress using Heisenberg's new ideas and before the end of 1925 he had derived the hydrogen spectrum from the new theory. This result was important in securing credibility for Heisenberg's theory.

Pauli was awarded the Nobel Prize in physics for 1945. He was a Foreign Member of the Royal Society of London and a member of the Swiss Physical Society, the American Physical Society and the American Association for the Advancement of Science. He was awarded the Lorentz Medal in 1930.