The term chloride refers either to a chloride ion (Cl−), which is a negatively charged chlorine atom, or a non-charged chlorine atom covalently bonded to the rest of the molecule by a single bond (−Cl). Many inorganic chlorides are salts. Many organic compounds are chlorides. The pronunciation of the word "chloride" is /ˈklɔːraɪd/.

The chloride ion is an anion (negatively charged ion) with the charge Cl-. Chloride salts such as sodium chloride are often soluble in water. It is an essential electrolyte located in all body fluids responsible for maintaining acid/base balance, transmitting nerve impulses and regulating liquid flow in and out of cells. Other examples of ionic chlorides are calcium chloride CaCl2 and ammonium chloride [NH4]Cl.

The chloride is also a neutral chlorine atom covalently bonded by a single bond to the rest of the molecule. For example, methyl chloride CH3Cl is an organic compound with a covalent C−Cl bond in which the chlorine is not an anion. Other examples of covalent chlorides are carbon tetrachloride CCl4, sulfuryl chloride SO2Cl2 and monochloramine NH2Cl.