Charles Édouard Guillaume (15.02.1861-13.06.1938) was a Swiss physicist. He was born in Fleurier. He graduated from the Zurich Polytechnic (1882). From 1883 he worked at the International Bureau of Weights and Measures at Sèvres (director from 1905).
His work was mainly in the field of metrology. He gave a new value for the volume of 1 l, investigated the source of the errors of mercury thermometers and proposed corrections for them (1889), and studied nickel-steel alloys, creating invar, elinvar and other alloys used in high-precision instruments and measuring standards (1899). For his work in the field of precision physics he was awarded the Nobel Prize in 1920.
A member of a number of academies of sciences and scientific societies, including the USSR Academy of Sciences (1924).