Cornelis Jan Bakker (11 March 1904 – 23 April 1960)[1] was a Dutch physicist and second Director General of CERN.

In the following his interest in nuclear physics grow and he started during World War II in cooperation with August Heyn with the development of a cyclotron for Philips.

After the war Bakker replaced Gorter as a professor of physics and director of the Zeeman Laboratory at the University of Amsterdam in 1946.

In 1951, Bakker was invited by Professor Pierre Auger (then director of the scientific department of UNESCO) to join a group of eight experts which should make plans about the future CERN.

During his funeral Bakker's work and commitment to CERN and science was repeatedly touted by politicians and researchers, such as John Adams (his successor as director general) or Jo Cals.