Leistus tanaognathus is a species of ground beetle found in the Yunnan Province, China.

[1] The color scheme in this species is black, reddish brown, and pale red.

The pronotum is shiny but the rest of the body is relatively matte, although the elytra are slightly iridescent.

[1] The species is only known from one specimen from Nankang Yakou, Baoshan County in the Yunnan Province.

80 specimens of L. gaoligongensis, a species described at the same time as L. tanaognathus, were found in the same place.