Bertha Swirles, Lady Jeffreys (22 May 1903 – 18 December 1999) was an English physicist, academic and scientific author who carried out research on quantum theory in its early days.

She was associated with Girton College, University of Cambridge, as student and Fellow, for over 70 years.

She also carried out research at the University of Göttingen under Max Born and Werner Heisenberg.

She continued her research into quantum theory, but also expanded her work to include seismology.

[4] In 2016 the Council of the University of Cambridge approved the use of Swirles's name to mark Swirles Court, which consists of 325 graduate student rooms, leased by Girton College, within the North West Cambridge Development.