A machine pistol shares several properties of the semi-automatic handgun and the sub-machine gun. Machine pistols are ordinarily magazine-fed and self-cocking. Such a pistol is designed to be held and used in a single hand but almost always requires the use of both hands to control.

Originally machine pistol derived from Maschinenpistole, the German term for the sub-machine gun. Today it is more often used to describe very small sub-machine guns such as the MAC-10 and the Mini-Uzi, although the line between machine pistols and sub-machine guns is quite blurry. Additionally, some fully automatic handguns such as the GLOCK 18 and the obsolete Mauser C96 would qualify as machine pistols.