Christian Leopold von Buch (26 April 1774 – 4 March 1853), usually cited as Leopold von Buch, was a German geologist and paleontologist born in Stolpe an der Oder (now a part of Angermünde, Brandenburg) and is remembered as one of the most important contributors to geology in the first half of the nineteenth century.

His scientific interest was devoted to a broad spectrum of geological topics: volcanism, petrology, fossils, stratigraphy and mountain formation.

Buch studied with Alexander von Humboldt under Abraham Gottlob Werner at the mining school in Freiberg, Saxony.

In 1802 he published Entwurf einer geognostischen Beschreibung von Schlesien ("The Geognosy of Silesia"), which became the first volume of his Geognostische Beobachtungen auf Reisen durch Deutschland und Italien ("Geognistic Observations while Travelling through Germany and Italy", see below).

The aspect of the Puy de Dôme, with its cone of trachyte and its strata of basaltic lava, induced him to abandon as untenable the doctrines of Werner on the formation of these rocks.

This furnished the materials for his work entitled Reise durch Norwegen und Lappland ("Travels in Norway and Lapland", Berlin, 1810).

These volcanic isles furnished the starting point from which Buch commenced a regular course of study on the production and activity of volcanoes.

When he published his memoirs and observations about his excursion, he introduced the Spanish word "Caldera" (meaning "Bowl") into the geological and scientific vocabulary.