Herbert Arthur Stuart (27 March 1899, Zurich – 8 April 1974, Hanover) was a German experimental physicist who made contributions in molecular physics research. During World War II, he was director of the experimental physics department at the Technische Hochschule Dresden. From 1955, he was the head of the high polymer physics laboratory at the University of Mainz. From 1920 to 1925, Stuart studied at the University of Würzburg and the University of Göttingen. In 1925, he was awarded his doctorate under James Franck at the University of Göttingen; his thesis was on resonance fluorescence of mercury vapor. He then went to work and study with Otto Stern, director of the "Institut für physikalische Chemie" (Institute for Physical Chemistry) at the Universität Hamburg and then with Richard Gans, director of the II. Physikalische Institut (Second Physics Institute) at the Albertus-Universität Königsberg (today, the Immanuel Kant State University of Russia). He completed his Habilitation in 1928, with an Habilitationsschrift on the temperature dependency of dielectric constants in gases and vapors. From 1928, Stuart was a Privatdozent and he did research on the Kerr effect and light scattering. In 1930, he was Rockefeller Foundation Fellow at the University of California, Berkeley, specializing in molecular structure research. From 1935, he was an untenured ausserordentlicher Professor (extraordinarius professor) and substitute director at the Albertus-Universität Königsberg. From 1936 to 1939, he substituted in the theoretical physics chair at the Friedrich-Wilhelms-Universität (today, the Humboldt-Universität zu Berlin), which had been vacated by Erwin Schrödinger. From 1939 to 1945, he was an ordentlicher Professor (ordinarius professor) and director of the experimental physics department at the Technische Hochschule Dresden (today, the Technische Universität Dresden). At Dresden, he began studying the viscosity and both light and electron scattering of macromolecules.