Theodor Weyl (8 January 1851 – 6 June 1913) was a German chemist and hygienist born in Berlin. He studied at the universities of Heidelberg, Berlin and Strasbourg, earning his doctorate in 1872 with a dissertation on animal and . Following graduation he worked as an assistant in the physiology laboratory at Berlin, shortly afterwards becoming an assistant professor at the University of Erlangen. During his tenure at Erlangen he spent the winter of 1880–81 performing research on the electric organs of rays at the Stazione Zoologica Anton Dohrn in Naples.