高层云(英语：Altostratus (cloud))是中云的一类，于2000米以上高空形成，像一种带有条纹的幕，颜色多为灰白色或灰色，有时有一点微蓝色，有时较为均匀，但云底没有明显的起伏。高层云的明暗程度会因云的厚度差异而不同。

高层云下有两个云属：

Altostratus is a middle altitude cloud genus belonging to the stratiform physical category characterized by a generally uniform gray to bluish-green and sheet or layer. It is lighter in color than nimbostratus and darker than high cirrostratus. The sun can be seen through thin altostratus, but thicker layers can be quite opaque.