Tetheella is a monotypic moth genus in the family Drepanidae described by Werny in 1966.

Its single species, Tetheella fluctuosa, the satin lutestring, was described by Jacob Hübner in 1803.

It is found from western Europe across the Palearctic to Kamchatka, Sakhalin Island, Korea and Japan.

The subterminal is whitish, waved, preceded on the costa by an oblique dark fuscous dash.

The larva is yellow whitish; dorsal, fine subdorsal, and lateral lines fuscous; head reddish-ochreous, brown-marked.