氯乙醛，结构式ClCH₂CHO。

无色具刺鼻辛辣气味的液体。易燃；有毒，具酸腐蚀性，对皮肤和粘膜有刺激性。溶于水、甲醇、乙醚、丙酮。40％水溶液为无色透明液体；浓度超过50％时析出半水物片晶，半水物溶于水、乙醇和乙醚。

Chloroacetaldehyde is the organic compound with the formula ClCH₂CHO. Like some related compounds, it is highly electrophilic reagent and a potentially dangerous alkylating agent. The compound is not normally encountered in the anhydrous form, but rather as the hydrate (acetal), ClCH₂CH(OH)₂. Chloroacetaldehyde is a useful intermediate in the synthesis, e.g. of 2-aminothiazole or many pharmaceutical compounds. Another use is to facilitate bark removal from tree trunks.