氯化钠是食盐的主要成分，化学式为NaCl。氯化钠是海水中盐分的主要组成部分，是最常见的调味料。摄取过量的盐易得高血压。

氯化钠的晶体形成立体对称。

其晶体结构中，较大的氯离子排成立方最密堆积，较小的钠离子则填充氯离子之间的八面体的空隙。每个离子周围都被六个其他的离子包围着。

这种结构也存在于其他很多化合物中，称为氯化钠型结构。

Sodium chloride /ˌsoʊdiəm ˈklɔːraɪd/, also known as salt or halite, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. Sodium chloride is the salt most responsible for the salinity of seawater and of the extracellular fluid of many multicellular organisms. In the form of edible or table salt it is commonly used as a condiment and food preservative. Large quantities of sodium chloride are used in many industrial processes, and it is a major source of sodium and chlorine compounds used as feedstocks for further chemical syntheses. A second major consumer of sodium chloride is de-icing of roadways in sub-freezing weather.