The Caucasian grouse or Caucasian black grouse (Lyrurus mlokosiewiczi) is a large bird in the grouse family. It is closely related to the black grouse (L. tetrix).
As with many gamebirds, the cock (male) is larger than the hen (female), measuring 50–55 cm compared to her length of 37–42 cm. The cock is very distinctive, with all-black plumage, apart from red eyebrows, and a long, deeply forked tail. The female Caucasian grouse is grey with dark barring, and has a cackling call.