碳酸盐岩是一种沉积岩的类别，最常见为石灰岩和白云岩两大类。其中石灰岩主要由霰石与方解石组成，后者则可提供白云石。

碳酸盐岩自寒武纪已广泛分布在全球各地，估计占沉积岩总量的20%至25%，属于重要矿产之一，可生产石膏、岩盐、钾盐及汞、锑、铜、铅、锌、银、镍、钴、铀、钒等，广泛应用在冶金、建筑、装修、工艺品、化工等行业上。碳酸盐岩亦经常保存着石油、天然气又或地下水，世上碳酸盐岩型油气田储量占总储量的50％，占总产量的60％。

Carbonate rocks are a class of sedimentary rocks composed primarily of carbonate minerals. The two major types are limestone, which is composed of calcite or aragonite (different crystal forms of CaCO₃) and dolostone, which is composed of the mineral dolomite (CaMg(CO₃)₂).