单膛室手枪（英语：Pistol），是最常见的一种手枪，只有一个膛室。由于在现代，单膛室手枪的使用比率极高，因此人们经常狭义地将单膛室手枪与手枪对等。在英语中，Pistol与Handguns的意义大致相同，但他们的分别是Handguns（手枪）是包括左轮手枪这种有弹巢的多膛室手枪。Pistol一词来自德语。

A pistol is a type of handgun. Some handgun experts and dictionaries make a technical distinction that views pistols as a subset of handguns; others use the terms interchangeably. Sometimes in usage, the term "pistol" refers to a handgun having one chamber integral with the barrel, making pistols distinct from the other main type of handgun, the revolver, which has a revolving cylinder containing multiple chambers. But UK/rest of Commonwealth usage does not always make this distinction, particularly when the terms are used by the military. For example, the official designation of the Webley Mk VI revolver was "Pistol, Revolver, Webley, No. 1 Mk VI". In contrast to Merriam-Webster the Oxford English Dictionary (a descriptive dictionary) describes 'pistol' as a small firearm to be used in one hand and the usage of "revolver" as being a type of handgun and gives its original form as "revolving pistol"