Hermann Gerhard Weyland (25 March 1888 in Sankt Ingbert – 20 January 1974 in Wuppertal) was a German chemist and botanist.
In collaboration with Richard Kräusel, he carried out significant paleobotanical investigations of Devonian flora.
He obtained his education at the University of Jena, receiving his doctorate in 1912 under the direction of Christian Ernst Stahl.
Following graduation, he worked as assistant to Wilhelm Pfeffer at the University of Leipzig and under Ludwig Knorr in Jena.
In 1931 he became an honorary professor at the University of Cologne, where in 1945–48 he served as interim director of the botanical institute.