The first few women with a physics Ph.D. from Leiden University Women entered Leiden University relatively late: The first students arrived in 1878 and the first Ph.D. degree is from 1903 (a thesis in law, by Adolphine Kok). The first four women with a physics Ph.D. all studied theoretical physics, and all four had Hendrik Lorentz as their promotor. This remarkable alignment might be explained by the circumstance that Lorentz's wife, Aletta Lorentz-Kaiser, was deeply involved in the women's rights movement in Leiden.
1912	Johanna Reudler (1880-1962) promotor Hendrik Lorentz Over de zwarte straling in ruimten van verschillenden vorm
1912	Geertruida Lorentz (1885-1973) promotor Hendrik Lorentz Over de theorie van de Brown'sche beweging en daarmede verwante verschijnselen
1918	Eva Bruins (1885-?) promotor Hendrik Lorentz Vraagstukken uit de theorie van het magnetisme
1919	Hendrika van Leeuwen (1887-1974) promotor Hendrik Lorentz Vraagstukken uit de electronentheorie van het magnetisme
1938	Anna Keesom (1909-1985) promotor Willem Keesom Enkele thermische eigenschappen van vloeibaar en vast helium
1938	Johanna Brunings (1912-?) promotor Hendrik Kramers Perturbations in the Ca I spectrum
1940	Henriëtte van der Horst (1883-1948) promotor Willem Keesom Metingen met den heliumthermometer: fundamenteele spanningscoefficient, kookpunt van zuurstof