German firearms inventor and manufacturer.

The son of a locksmith, Dreyse worked from 1809 to 1814 in the Parisian gun factory of Jean-Samuel Pauly, a Swiss who designed several experimental breech-loading military rifles. Returning to Sömmerda, he in 1824 founded a company to manufacture percussion caps. There he designed a series of “needle-firing guns,” rifles in which a needlelike pin pierced a percussion cap in the centre of a paper cartridge to strike the detonating material (usually mercury fulminate) that fired the bullet. A muzzle-loading model of 1827 was followed in 1836 by a bolt-action breechloader, which the Prussian army began to purchase in 1841. The high rate of fire of Dreyse's weapon overwhelmed enemy troops in the 1864 German-Danish War for the territories of Schleswig and Holstein, earning Dreyse papers of nobility from the emperor. The Dreyse rifle was the standard Prussian infantry weapon until the ascendancy of the Mauser rifle in the 1870s and '80s.

The factory founded by Dreyse and continued by his son Franz (1822–94) became, in 1901, part of the giant Rheinische Metallwaaren- und Maschinenfabrik AG of Düsseldorf (now Rheinmetall GmbH), a major supplier of weapons to the German military.