August Friedrich Gustav Werther (1 August 1815, Roßla – 29 June 1869, Königsberg) was a German chemist. He made contributions in both organic and inorganic chemistry, being known for his work in the field of analytical chemistry.
In 1843 he obtained his doctorate in Berlin, where he served as an amanuensis to Eilhard Mitscherlich. Afterwards, he worked as a chemistry instructor at the artillery and engineering school in Berlin. In 1853 he became an associate professor at the University of Königsberg, where in 1859 he was appointed a full professor of chemistry.
From 1853 onward, he was an editor of Otto Linné Erdmann's Journal für practische Chemie. The following are some of Werther's principal works: