水合氯醛（化学式：C₂H₃Cl₃O₂）又称水合三氯乙醛、2,2,2-三氯-1,1-乙二醇，是三氯乙醛的醛水合物，用作有机合成中间体、催眠药和抗惊厥药。

纯水合氯醛是无色透明有强烈辛辣气味的单斜片状结晶固体，味微苦，有挥发性。易溶于水、乙醇、氯仿、甘油、乙醚、丙酮、丁酮，微溶于苯、二硫化碳、石油醚、甲苯。遇碱分解为氯仿和甲酸盐。遇热释放出有毒有刺激性的气体。加热到98°C时分解为三氯乙醛和水。

Chloral hydrate is an organic compound with the formula C₂H₃Cl₃O₂. It is a colorless solid. It has limited use as a sedative and hypnotic pharmaceutical drug. It is also a useful laboratory chemical reagent and precursor. It is derived from chloral (trichloroacetaldehyde) by the addition of one equivalent of water.