Casimir Lefaucheux (French: [kazimiʁ ləfoʃø]; 26 January 1802 – 9 August 1852) was a French gunsmith. He was born in Bonnétable and died in Paris. Casimir Lefaucheux obtained his first patent in 1827. In 1832, he completed a drop-barrel sporting gun with paper-cased cartridges. In 1846 Benjamin Houllier improved on the Lefaucheux system by introducing an entirely metallic cartridge of copper brass. In 1858 the Lefaucheux pistolet-revolver became the first metallic-cartridge revolver to be adopted by a national government, becoming the standard sidearm of the French Navy.