碳酸氢钙（化学式：Ca(HCO₃)₂），是一种无机酸式盐。

产生碳酸氢钙最重要的化学反应即是以碳酸钙溶于二氧化碳水溶液而成碳酸氢钙，反应式如下：

碳酸氢钙微溶于水，但碳酸钙难溶。钟乳石的形状即是由微溶的碳酸氢钙与难溶的碳酸钙在一定二氧化碳浓度下的互相转变造成的。

碳酸氢钙只存在溶液中；将碳酸氢钙溶液蒸发则得到碳酸钙固体。

Calcium bicarbonate, also called calcium hydrogen carbonate, has a chemical formula Ca(HCO₃)₂. The term does not refer to a known solid compound; it exists only in aqueous solution containing the calcium (Ca), bicarbonate (HCO₃), and carbonate (CO₃) ions, together with dissolved carbon dioxide (CO₂). The relative concentrations of these carbon-containing species depend on the pH; bicarbonate predominates within the range 6.36-10.25 in fresh water.