Wolfgang Sartorius Freiherr von Waltershausen (December 17, 1809 – March 16, 1876) was a German geologist. Waltershausen was born at Göttingen and educated at the University of Göttingen. There he devoted his attention to physical and natural science, and in particular to mineralogy. Waltershausen's father, Georg, was a writer, lecturer and professor of economics and history at Göttingen, best known for his role of translator and popularizer of Adam Smith's Wealth of Nations.
During a tour in 1834-1835 Waltershausen carried out a series of magnetic observations in various parts of Europe. He then gave his attention to an exhaustive investigation of the volcano of Mount Etna, in Sicily, and carried on the work with some interruptions until 1843. The chief result of this undertaking was his great Atlas des Ätna (1858–1861), in which he distinguished the lava streams formed during the later centuries.
After his return from Mount Etna, Waltershausen visited Iceland, and subsequently published Physisch-geographische Skizze von Island (1847), Über die vulkanischen Gesteine in Sizilien und Island (1853), and Geologischer Atlas von Island (1853). Meanwhile he was appointed professor of mineralogy and geology at Göttingen, and held this post for about thirty years, until his death.