Thamnoecha is a monotypic moth genus in the family Sphingidae erected by Walter Rothschild and Karl Jordan in 1903.

Its only species, Thamnoecha uniformis, first described by Arthur Gardiner Butler in 1875, is known from the Himalayas.

Adults are on wing from March to August.

The larval food plant is thought to be chir pine (Pinus roxburghii).

This Sphinginae-related article is a stub.