Hadena caesia, also called the grey, is a species of moth of the family Noctuidae.

It has a scattered distribution all over Europe (see subspecies section).

Forewing blue grey, with a furry look, caused by dusky grey irroration; both folds tinged with fulvous; lines and markings often indistinct; upper stigmata pale, with yellow scales in their annuli; a dark antemedian band widened to inner margin and a less prominent dark submarginal cloud; a small dark blotch at middle of costa; hindwing dark fuscous, paler towards base; — manani Gregs.

from the Isle of Man and the Irish coast, is uniformly darker slate colour; — ab.

of Scandinavia is much darker, the forewing suffused with black; on the other hand [now full species Hadena clara] Stgr., from Armenia and Asia Minor, has the forewing greyer, with a pinkish tinge; the median area paler.