Franz Richarz (15 October 1860, in Endenich – 10 June 1920, in Marburg) was a German physicist.
His father, also named Franz Richarz (1812–1887), was a noted psychiatrist.
He studied mathematics and physics at the universities of Berlin and Bonn, receiving his doctorate in 1884 with the dissertation Bildung von Ozon, Wasserstoffsuperoxyd und Ueberschwefelsäure bei der Electrolyse verdünnter Schwefelsäure ("The formation of ozone, hydrogen peroxide and sulfuric acid during the electrolysis of dilute sulfuric acid").
In 1888 he obtained his habilitation and worked as a lecturer of physics at the University of Bonn.
[1][2] With Otto Krigar-Menzel, he conducted a series of experiments for determination of the gravitational constant and the Earth's mean density.