硫化钙（化学式：CaS）是碱土金属钙的硫化物，室温下为白色具有臭鸡蛋气味的固体，不纯时常带有黄色。它具有氯化钠型晶体结构，每个S与六个Ca八面体配位相连，每个Ca也以八面体结构与六个S配位。

用焦炭高温还原硫酸钙便可得到硫化钙，另一个产物是碳氧化物：

继续反应则得到氧化钙与二氧化硫：

潮湿空气中，硫化钙会发生水解，生成硫氢化钙、氢氧化钙和碱式硫氢化钙的混合物：

除硫化铍外，包括硫化钙在内的碱土金属硫化物都可作磷光体，因此性质及制备都曾被广泛研究过。它可作发光漆材料，也可用于医药、环保、重金属处理等工业中。类似的多硫化钙用作杀虫剂。

Calcium sulfide is the chemical compound with the formula CaS. This white material crystallizes in cubes like rock salt. CaS has been studied as a component in a process that would recycle gypsum, a product of flue-gas desulfurization. Like many salts containing sulfide ions, CaS typically has an odour of H₂S, which results from small amount of this gas formed by hydrolysis of the salt.